aPrepare to launch!a he bellowed. aMake ready to drop the anchor chain!a aWuh-wuh!a the banderbears bellowed back. Aye-aye.

With a mighty shudder and an ominous creak, the Skyraider began to lift up into the air. Twig let the heavy anchor chain fall away with a resounding clang.

aWe shanat need that where weare going,a he called to the others.

The tattered sails billowed. The sky ship listed to one side and pulled away from the black crag. Higher and higher the great sky vessel flew, calmly, sedately, until, all at once, the wind caught it from behind and sent it soaring up into the air so fast that Rookas head spun and his stomach did somersaults.

aThis is amazing!a he cried out. aIncredible! I canat believe that Iam actually flying on board a sky pirate ship!a Twig chuckled. aNeither can I, lad,a he said. aNeither can I. Sky above, but Iave missed it! The thrust of the sails, the sway of the weights a" the wind in my hair. Itas almost like the old days,a he said. aAs if I were a sky pirate once again.a Rook turned to him, his eyes bright with excitement. aBut you are!a he said.

Twig nodded slowly, as his fingers danced over the flight-levers. aAye, Rook, I suppose I am,a he said. His brow furrowed. aThe last of the sky pirates.a t was the darkest hour just before the dawn. A fine dew, glistening in the overhead lamplight, covered the surface of the crumbling Sanctaphrax rock. From a shadowy crevice came a soft, slurping noise. Something was stirring.

A long, glistening tentacle appeared, then another a" and the two gripped the rock and pulled. A dripping, jelly-like creature emerged. Three small round b.u.mps on the top of its head grew large, cracked open and eyed the surroundings suspiciously. The tentacles reached out again and dragged it forwards.

Where the creature pa.s.sed, the rock behind was left bone-dry, and as it slipped and slid about, it began to swell. Larger it became, larger and larger until, with a hiss and a spurt, three rear-tentacles suddenly uncoiled and squirted a thick, oily substance over the rock behind it. It had drunk enough.

The rubble ghoul slithered back down between the cracks in the broken rock. Having sated its thirst, it was now hungry.

Far, far above, a hammerhead goblin was also hungry. Ravenous, in fact. And thirsty. And cold. He stamped his great booted feet and pulled his black robes up against the icy air which, so high up the towering building, was cold enough to cover the wood of the jutting gantry with a feathery coating of frost.

aJust you wait till I get my hands on you, Gobrat, you useless, squint-eyed little runt!a he growled, and his breath came in dense puffs of cloud which glowed and squirmed in the yellow light of the hanging oil lamps. He paced back and forwards, slapping his arms against each other in an attempt to get warm. aLeaving me here to do your guard-duty!a he complained. He should have been relieved at nine hours the previous night; now, the first rays of early morning sun were already lining the distant clouds with silver. aAll through the night Iave been standing here!a he muttered angrily. aIall stove in your skull! Iall break every bone in your body! Ialla"Waaargh!a The heel of his boot skidded on an untouched patch of frost, and sent the goblin crashing to the floor. His heavy horned helmet came loose as his head slammed viciously down on the cold, hard wood with a loud crack!

Dazed, the hammerhead sat up. He saw the helmet scudding towards the edge of the gantry. Heart hammering furiously, he lunged forwards and grasped one of the helmetas curving horns just as it was about to tumble down from the high gantry.

aThat was a close one,a he told himself grimly. aYou take care, now, Slab.a He climbed to his feet and put the helmet back on his head. If head lost it, the guard master would have clapped him in irons and thrown him into solitary confinement for a week as punishment.

Slab checked the rest of his equipment a" the curved knife at his belt, the powerful-looking crossbow on his back, the heavy hooked pikestaff a Everything, he was relieved to discover, seemed to be in order.

Just then, in the distance, far below, came the sound of the bell at the top of Vox Verlixas Undertown palace tolling the hour. It was six. Head now been on duty for eighteen hours! He stared out across the chasm of open sky as the sun slowly wobbled up above the horizon, shielding his eyes as the light grew dazzling. He looked down.

There, below, were the Stone Gardens, their once mighty rock-stacks now a mess of broken rubble littering the dead rock. Screetown and Undertown were wreathed in mist and, in the middle distance, the Great Mire Road was already teeming with countless tiny individuals as it wound its way back into the murky gloom and disappeared. For despite the bright start to the day, there were dark clouds rolling in from the Deepwoods far to the north-west, threatening rain, maybe even a lightning storm a aA storm, after all this time.a Slab hawked and spat. aThatad show those accursed librarian knights,a he growled. aThink theyare so clever, so they do a" with their books and learning and their pathetic little skycraft.a He stared up into the great banks of cloud, praying for a lightning bolt to strike the top of the tower. aBut theyall learn one day. When Midnightas Spike heals the rock and we return to the skies, then theyall seea"a aStrength in night!a came a gruff voice behind him, and Slab turned to see a brawny, heavily tattooed flat-head who bore the scars of many a battle standing in front of him, his clenched right fist pressed against his breastplate in ritual greeting.

aAh, Bragknot, strength in night!a Slab replied, and saluted in response. aAm I glad to see you. Gobrat never showed up, the littlea"a aGobratas gone missing,a said Bragknot. aNo-one seems to know where he is.a aSoused on woodgrog and slumped in some dark corner, if I know him,a Slab muttered bitterly. He yawned.

aEighteen hours without a break Iave been up here. Eighteen hours aa Bragknot shrugged. aIt happens,a he mumbled un a" sympathetically and looked all around, scanning the townscape below and squinting into the distance. aQuiet watch, was it?a he said. aNo problems?a aNone,a said Slab.

The flat-head nodded towards the great banks of cloud looming closer. aLooks like rain,a he commented. aJust my luck!a aYeah, well, Iall leave you to it,a said Slab. aIam off to get my head down.a aYou do that,a said Bragknot, turning towards him. aIalla"a He gasped and looked back over Slabas shoulder. aSky above! What is that?a Slab chuckled. aIam not falling for that one again,a he said.

aI mean it, Slab!a said Bragknot. aItas a itas aa He grabbed the smirking hammerhead by the shoulders and twisted him round. aLook!a Slabas eyes widened. His jaw dropped. This time, Bragknot had not been playing one of his stupid games. There really was something there.

aIt canat be,a he whispered, trembling with awe as a great ghostly vessel emerged from the cover of dark, swirling cloud.

Too young to have seen one before, Slab stood transfixed, staring in disbelief at the vast, solid sky ship as it swept gracefully down through the air towards them. With its huge billowing sails and ma.s.sive hull, it was more awesome than he could ever have imagined.

aB-but how?a he faltered. aHow is it possible?a He shook his head. aA sky ship still flying a Where did it come from?a aNever mind all that!a bellowed Bragknot. aSound the alarms! Raise the guard! Mount the harpoons! Come on, Slab! We musta"a Just then Slab heard a high-pitched whistle and a soft thud. He spun round. Bragknot stood there, swaying slowly back and forwards on the spot. He looked back at Slab, his eyes filled with fear and confusion as his fingers closed gingerly round the ironwood bolt lodged in the side of his neck. His throat gurgled. Blood gushed down over his black robe. The next moment he staggered backwards and toppled over the edge of the gantry, dropping down silently out of sight.

A second bolt whistled in over Slabas head and embedded itself in a broad crossbeam behind him. A third shattered the hanging-lamp. It was followed by a dozen or more arrows, hissing in through the air and quivering where they struck.

aTo the gantries!a Slab roared. aWeare under attack!a aWhat is it? a Whatas going on?a several voices cried out from above and below him.

aOver there!a shouted someone from an upper gantry pointing into the cloud, now swirling round the tower.

aA sky ship!a bellowed another.

aItas turning this way!a shouted yet another, a telescope raised to his eye. aAnd itas got heavy weaponry aboard!a A loud rasping klaxon sounded, followed by another and another a Soon, the whole Tower of Night echoed to the clamour of the Guardians answering the call to arms.

Head down, Slab dashed back along the exposed gantry. Skidding awkwardly on the slippery wood, he tumbled in through the doorway. Behind him there was a flash and an almighty splintering crash as an incoming ball of flaming ironwood severed the jutting gantry and sent it hurtling down below. Had it landed a second earlier, he too would be hurtling down with it.

Slab climbed shakily to his feet. All round him the air was filled with bellowed orders and screeched commands. Doors banged and shutters slammed as section after section within the great tower was sealed off to prevent an invasion. Heavy boots pounded up and down stairs as well-armed, black-robed Guardians hastened to the west side of the tower to repel the great attacking sky ship.

In all the chaos and confusion no-one noticed a small skycraft as it swooped down through the dark, swirling mist on the far side of the tower.

With the cloud as cover, the sky ship spat out a flaming salvo at the Tower of Night. Gantries splintered and shattered; great holes appeared in the walls and, where the heavy b.a.l.l.s of flaming ironwood penetrated, small fires broke out.

Inside the tower the Guardians of Night were in turmoil, with the guard masters barking out a stream of orders.

aShove that broken beam back into place!a aDouse that fire!a aLoad the harpoons!a aPrime the catapults!a While some effected makeshift repairs and others smothered the flames with water and sand, small groups ventured out onto the jutting weapon-platforms where the heavyweight weaponry stood on plinths, bolted to the floor. Working in threes, they took up their battle positions. At the harpoon-turrets, one jumped into the firing seat and primed the shooting mechanism, one loaded a harpoon into the long chamber, while the third grabbed the wheel at the side of the turret and began turning. Slowly, as the sequence of internal cogs moved, the whole mechanism swung round. Then, seizing a second wheel, he altered the angle of the long barrel until the huge harpoon was pointing directly at the attacking sky ship. At the swivel catapults a similar process was taking place. When the launch trajectory had been secured, the guards a" two at a time a" heaved enormous, heavy boulders into each of the ladle-shaped firing bowls.

aFire!a roared a guard master. Then another, higher up, bellowed the same command. And another, and another.

aFire! a Fire! a Fire!a A volley of harpoons and rocks exploded from the Tower of Night and hurtled towards the sky ship. One of the harpoons struck the starboard bow; a second skittered across the lower deck. Further back, a boulder dealt a glancing blow to the stern. All would have shattered a small skycraft, but the mighty sky ship barely seemed to flinch.

The Guardians of Night reloaded. The Skyraider rose up higher in the sky. The harpoon-turrets and swivel catapults were realigned.

aFIRE!a The second bombardment did even less harm than the first, with not a single harpoon or boulder meeting its target. Peering through their telescopes into the swirling cloud, the guard masters saw the bearded figure at the helm a" resplendent in satin frock coat and tricorn hat a" barking commands of his own. The main-sail billowed. The stern hull-weights dropped. Abruptly, the hovering sky ship soared upwards, returning fire as it did so.

aTheyare heading for Midnightas Spike,a someone cried.

aDefend the spike!a aDefend her with your lives!a aFIRE!a A third salvo of rocks and harpoons soared into the sky, a single rock hitting amidships, where a lone banderbear feverishly tended the great flight-rock. The bander-bears at the rear of the ship replied with a heavy bombardment of the flaming ironwood b.a.l.l.s. The walls of the tower suffered more damage and one harpoon-turret was destroyed by a direct hit. Two Guardians a" one up high on a look-out gantry and one on a weapon-platform some way below a" were struck by arrows simultaneously. The pair of them keeled forwards and, one after the other, tumbled down through the air as in some strange and terrible dance.

aMore fire-power!a roared a guard master.

aReinforcements to the spike chamber at once!a bellowed another.

aAlert the Most High Guardian!a aCall Orbix Xaxis!a Slab crouched down on the boards and peered out through the shattered wall. He had neither harpoon-turrets nor swivel catapults up here at the look-out gantry, yet the death of his comrade-in-arms would be avenged. With trembling hands, he raised the sight of the crossbow to his eye, slid the ironwood bolt into place and ratcheted the string back.

aThis is for Bragknot,a he muttered grimly.

The sky ship loomed up before him, thick clouds of mist swirling around it. Slab lowered his head. He took aim. For the briefest of moments, the sky ship drew level. He fired the crossbow.

There was a thump. A tw.a.n.g. The bolt shot into the air and disappeared into the thick misty cloud. Slab held his breath. The next instant, rising up above the cacophony of noise from the tower itself, there came an anguished yodelling cry and, as the cloud fleetingly thinned out, he saw a banderbear clutch at its heart and fall off the sky ship.

aGot you!a Slab snarled, as the great hairy beast tumbled down through the air. He raised the crossbow to his eye a second time. As he looked through the view-finder, he saw three great flaming b.a.l.l.s hurtling straight towards him.

Before he had a chance even to cry out, the ironwood b.a.l.l.s struck a" tearing apart the whole upper section of the tower and snuffing out the life of the hammerhead guard. The building shook from top to bottom. The sky ship rose higher, almost level with the great spike that topped the tower.

aTheyare using grappling-hooks!a screeched a guard from the base of the spike as a heavy three-p.r.o.nged hook abruptly flew out from the Skyraider and hurtled towards it. aTheyare trying to destroy Midnightas Spike!a aSacrilege!a bellowed another.

aDestroy the invaders!a roared yet another.

The Guardians intensified their efforts to repel the attacking sky ship with volley after volley of boulders and harpoons, arrows and crossbow bolts a" and anything else they could lay their hands on. The air trembled with the din of battle. The Skyraider responded with arrows and crossbow bolts of its own, and the great flaming b.a.l.l.s of ironwood which tore chunk after chunk from the dark tower. Numerous goblins, trogs and trolls in the black robes of the Guardians of Night plummeted to their deaths. Another grappling-iron clanged against Midnightas Spike. A second banderbear was struck a On the other side of the tower the skycraft approached. Lightly, stealthily a" like a woodmoth on the wing a" it flitted up and down the great east wall, its rider looking for a place to enter. Finally he swooped down onto a small, jutting gantry, two-thirds of the way up, which appeared to be deserted.

The rider dismounted. As he tethered the skycraft securely to eye-hooks screwed into the wall, the weak milky sunlight penetrated the thick cloud and shone into his face. The youth a" jaw set and brow creased with concentration a" turned towards the small, dark entrance and disappeared inside.

As Rook peered into the gloom, the dark, menacing atmosphere a.s.saulted his senses like a battering-ram slamming into locked fortress doors. It was dark within the tower despite the hanging-lamps, and the stench of death and rancid decay was overpowering. Rook faltered a" numb, dumbstruck, incredulous that anyone could have created so evil a place.

He could hear voices, countless voices. Their m.u.f.fled moans and feeble cries echoed in the darkness, a soft and terrible accompaniment to the ba.s.s rumbles and furious percussion of the battle raging far above him. aPoor wretches,a Rook murmured. aIf only I could save you all.a As his eyes grew accustomed to the gloom, he wrapped the cloak of nightspider-silk round his shoulders and ventured further into the tower. He found himself in a confusing labyrinth of narrow walkways and rickety flights of stairs sandwiched between the outer wall of the tower and an inner wall. At wild irregular angles, the wooden stairways zigzagged off in all directions a" above and below him, and away to both sides. The sound of the hopeless, groaning prisoners grew louder, the foul stench more intense.

Rookas eyes followed the path of the walkway he was standing on. It led to a small, square landing, before doubling back on itself and rising steeply further up. At the far side of the landing, set into the shadowy inner wall of the tower, was a door.

Is that one of the cells? he wondered. There was only one way to find out.

Rook dashed up the stairs. On the landing, as he approached the heavy, wooden door, he saw what looked like markings. He pulled the sky-crystals from his pockets and, holding them together, used the pale light they emitted to examine the door more closely. Several names had been scratched crudely into hard wood: RILK TILDERHORN, LEMBEL FLITCH, REB MARWOOD, LOQUBAR AMSEL a Each of them had a line gouged through them. Only the name at the bottom remained untouched.

aFinius Flabtrix,a Rook whispered. aAn academic, by the sound of him.a There was a shuttered spy-hole in the door and heavy bolts at the top and bottom. Rook reached forwards, slid aside the spy-hole cover and quickly glanced inside. He couldnat make out anything in the blackness, but the stench intensified. Gingerly he reached up and drew the top bolt across; then the bottom bolt. Slowly he pushed the heavy door open and looked in.

With no walls, no chains, no bars, the cell was nothing like he had ever seen. A narrow set of steps led from the door down to a single ledge, which jutted out from the wall into a cavernous atrium beyond. Apart from the door which, when shut, formed a smooth, unbroken part of the inward-sloping wall, the only way out was to step off the ledge and tumble down through the fetid air to certain death below. Looking out into the atrium, Rook could make out countless other ledges, each connected by their own steps to individual cell doors.

Appalled, his gaze fell upon the individual at the corner of the ledge before him. Curled up in a foetal ball, he lay on a stinking mattress of straw, bony arms hugged round bonier legs; his robes in tatters, his breath uneven, rasping. Long, matted hair hung down over his face. In places it had fallen out in clumps, leaving angry scab-encrusted patches all over his scalp. His beard was thick and soiled; his skin was covered in grime and red, weeping sores a" the result of scratching and scratching with his filthy, jagged nails to relieve the intolerable itching of the tick-lice which burrowed beneath the surface to lay their eggs.

aFinius? Finius Flabtrix,a said Rook softly, moving closer. aProfessor Finius Flabtrix?a The breathing quickened. The eyelids flickered and opened for an instant but, though the eyes stared in his direction, Rook knew that they had not seen him. They closed again.

aNot my fault,a the old professor murmured, his voice hoa.r.s.e and faltering. aNot my fault. Not my fault aa aItas all right, I wonat hurt you,a Rook whispered, tears welling up in his eyes.

The professor ignored him, lost in his own private torment. Rook turned and made his way carefully back up the stairs and out through the cell door. There was no time to lose; the Skyraider couldnat keep the Guardians occupied for ever. He must find Cowlquape and get out of this terrible place.

He hurried down another walkway, and saw a row of cell doors embedded in the inner wall. Quickly, by the glow from the sky-crystals, he checked the names scratched into each door: JUG-JUG ROMPERSTAMP, Rook read. ELDRICK SWILL. RAIN HAWK III. SILVIX ARMENIUS. GROLL a If the names were anything to go by, then the prisoners came from every walk of Edge life. Merchants and academics. Slaughterers, goblins and trolls. A former sky pirate a At some, Rook simply read off the name and continued without stopping. At others, he paused to look through the spy-hole a" though each time he did so, he wished that he had not. The abject creatures inside were too terrible to witness. Jabbering. Twitching. Deranged. Some rocked slowly back and forwards, some ranted and raved, some paced round and round mumbling beneath their breath, while others a" the worst of them; those who had given up all hope a" simply lay on the ledge, waiting for death to come and embrace them.

A fiery anger spread through Rookas body. Curse the Guardians of Night! he thought bitterly. aThe dungeons are an abomination! An affront to every living creature in the Edge a" to life itself! Why, if I was ever uncertain whether the war between the librarian knights and the Guardians of Night was a just one, then here is the proof,a he told himself. aThis is truly a battle between good and evil!a aWell said,a came a voice close by.

Rook jumped. aWhoas that?a he whispered.

aOver here,a said the voice.

Rook approached a cell door. He looked down. CODSAP was scratched into its heavy, dark wood.

aOpen the door,a came the voice. aGive it a good shove. A really good shove! Go on!a Rook unbolted the door, and gave it a hard push. There was a thud, and a m.u.f.fled cry. Rookas heart missed a beat. What had happened? What had he done? He thrust his head inside the doorway just in time to see a green, scaly creature tumbling back off the stairs and down into the yawning void of the great atrium.

aNo!a Rook bellowed, his howl of anguish spinning round and round the rank air. aIam sorry! I aa Suddenly, there was a voice, speaking to him inside his head. aThank you, thank you, friend, for releasing me when I lacked the courage to jump aa The voice fell still.

Rook flinched. How long had the poor creature waited on the stairs for someone to come and end his suffering? He slammed the door shut with a helpless fury, the clang echoing loudly through the tower.

aOuch,a came a voice from the shadows, somewhere to his left. aOh, my poor head. I knew I shouldnat have had all that woodgrog. Is that you, Slab?a Rook drew his knife and silently followed the direction of the voice. There, just ahead, slumped in the corner of a landing, head in hands, was a sleepy flat-head goblin in the black robes of a Guardian of Night, a crossbow and an empty jar by his side.

In an instant Rook grabbed the crossbow, kicked the jar away and thrust his knife at the goblinas throat.

aY-y-youare not Slab,a he stammered. Rook could see the whites of his eyes as the goblinas frightened face looked up into his. Wh-who are you?a aNever mind who I am,a Rook whispered, stepping back and levelling the crossbow at the white gloamglozer emblem on the goblinas chest. aWho are you?a aIam Gobrat. Iam just a poor guard. A warder. Please donat hurt me.a He paused, a frown crossing his broad features. aYouare one of them librarian knights, ainat you? Oh, please have mercy, sir. Iave never hurt no-one, honest I havenat.a aAnd yet you wear the black robes of the Guardians of Night,a said Rook, a cold anger in his quiet voice.

aThey took me in, sir, when I was starving in Undertown. I had nothing. They fed me and clothed me a" but Iam just a poor goblin from the Edgewater slums at heart. Please donat kill me, sir.a aA warder, you say,a said Rook.

aYes, sir. Iam not proud of it, sir a" but I does what I can for the poor wretches locked up here aa Rook raised the crossbow to silence the flat-head. aTake me to the cell of Cowlquape Pentephraxis and Iall spare your miserable life,a he said.

The goblin groaned. aItall be more than my lifeas worth if the High Master finds out Iave led you to Cowlquape.a aItall be more than your lifeas worth if you donat,a said Rook, pulling back on the crossbow trigger.

aAll right! All right!a The goblin got to his feet shakily. aFollow me, sir, and be careful where youare pointing that there crossbow.a Rook followed the flat-head through the endless maze of walkways and staircases, down into the depths of the Tower of Night. As they continued, there was a loud crashing sound from high up above the atrium, and the stairs rattled as the tower shook. I suppose thatas your lot up there/said Gobrat, acausing all that commotion.

It wonat do any good, you know. You never learn! Skycrafts is no match for tower weapons.a aJust keep walking,a said Rook, jabbing the crossbow into his back. aHow much further?a aNot far,a said Gobrat, with a mirthless laugh. aWeare almost at the lower depths now, young sir.a With the flat-head in front, they made their way down a sloping flight of stairs. Gobrat stopped at a heavily bolted door. aCowlquape Pentephraxis,a said Rook, reading off the name. aThis is it!a Gobrat scowled. aThere. Now take my advice and get out of here smartish. The guards will be swarming all round once theyave dealt with your comrades, and now Iave helped you, my life isnat worth an oakapple pip!a The goblin pulled off his robe and threw it to the ground. aI suppose itas back to the Edgewater slums for old Gobrat a" if the rubble ghouls donat get me.a Rook waved the flat-head away. aYouave been of valuable service to the librarian knights,a he said. aFare you well, Gobrat.a With the flat-head gone, Rook returned his attention to the cell door. Having checked that the stairs inside were clear, he slid the bolts across and pushed the door open.

aIs that you, Xanth?a came a cracked, frail voice.

aNo, Professor,a said Rook. aIam a librarian knight. Iave come to rescue you.a He descended the stairs, down to the primitive, wooden ledge. Here in the depths of the tower, the stench was indescribable. The former Most High Academe of New Sanctaphrax looked up at him. His body was bent and painfully thin. His grey hair, long and unkempt, his robes threadbare. Worst of all were his eyes. Filled with the memories of horrors too terrible to forget, they stared ahead, lifeless, dull, unblinking a aProfessor, we must leave now,a said Rook. aTime is running out.a aLeave aa Cowlquape murmured. aTime aa Rook leaned forwards and, taking the professor gently but firmly by the arm, hoisted him up onto his feet. Then, taking his weight a" which wasnat much a" he guided him up the stairs.

aWait! Wait!a Cowlquape called urgently, and broke away. He returned to the ledge, grabbed a roll of papers and barkscrolls and thrust them under his arm. He looked at Rook, a little smile playing round his mouth. aNow I am ready to leave,a he said.

Up at Midnightas Spike the battle raged on. The crew of the Skyraider was down to five now. Rummel, the huge, black banderbear, had fallen first, fatally wounded by Slabas crossbow bolt. Meeru was next to fall, skewered by one of the great harpoons and torn away from the sky ship. Mindless with grief, his brother Loom had thrown himself off the stern after his beloved twin.

But Twig hadnat time to mourn the loss of the three brave banderbear volunteers, for Molleen had yodelled to him to come at once to the flight-rock cage. Calling Wumeru over, and telling her to hold the helm steady, Twig hurried down to the old banderbearas side.

aWuh-wuh!a Look! Molleen pointed at a livid scar in the glowing flight-rock. aWegga-lura-meeragul. Wuh!a The rock is wounded. I thought the weapons of the Dark Ones had not hurt it a" but look, Captain!

Twig looked. Where the Guardiansa rock had struck, a deep crater had formed. It was growing like an ulcer, eating away at the flight-rock.

aContamination!a Twig gasped. aWe havenat much time. Do what you can, Molleen, but be prepared to abandon ship.a He hurried back to the helm.

Despite her best attempts to keep it buoyant a" dousing the flight-lamps, drenching the rock with chilled sand and, with Wumeru now by her side, desperately operating the cooling-fans a" the rock continued to disintegrate. The crater in its surface became wider, deeper, and a growing trickle of dusty particles showered down through the air.

aGive me as much time as you can!a Twig shouted across to Molleen. aWe canat abandon Rook now,a he added, mopping the beads of sweat from his forehead. His hands darted over the bone-handled levers in a furious blur as he carried out ever-finer adjustments to the sails and weights in an effort to keep the leaning, lurching sky ship from rolling right over.

But he was fighting a losing battle. With every pa.s.sing minute the flight-rock became less and less buoyant. If the Skyraider was to remain airborne, it would have to be made lighter.

aWeeg!a Twig bellowed. aTo the hull-rigging with you! I want you to cut the weights.a aWuh-wuh,a he shouted back. Cut the weights, Captain? But weall become unstable.

aItas a chance weall have to take,a Twig shouted back. aStart with the klute-hull-weights, then the peri-hull-weights. And if thatas not enough, move on to the prow-and stern-weights a Sky willing, itall give us the lift we need.a He frowned. aNow, Weeg!a Grunting unhappily, the lanky banderbear hurried off to carry out the commands. Twig fingered the various bone and wood amulets around his neck. Far below him, on the platform beneath Midnightas Spike, stood a figure in black robes, fluttering in the mist, with a curious muzzle-like mask covering most of his face.

aWuh! Wuh!a Molleen cried out. The flight-rock! Itas broken in two!

aHold it steady!a Twig told her. aJust a little bit longera"a At that moment a lufwood-flare soared up from the other side of the tower and blazed in the sky far above their heads, a brightly glowing streak of purple.

Twig gritted his teeth. aThank Sky!a he whispered. aItas the signal! Rook is waiting for us!a Just then Weeg must have severed the first hull-weight, for the sky ship gave a sudden jolt and rose up several strides into the air. A salvo of harpoons sailed harmlessly beneath its hull.

aHold tight, Cowlquape, old friend,a said Twig grimly. aWeare coming to get you.a Down on the platform at the base of Midnightas Spike, Orbix Xaxis stared up at the bright purple light suspiciously aIt must be some sort of signal,a he said. He looked across at the Skyraider; his eyes narrowed. aWhile you, up there, were keeping us busy aa he said slowly, thoughtfully, athere was something else afoot. I smell a rat aa He paused. aThe dungeons!a aIall check them at once,a said the sallow, shaven-headed youth by his side, dashing off as fast as he could down the broken flight of stairs.

aYou, Banjax,a the Most High Guardian shouted at one of the guard masters close by. aTake two dozen Guardians and scour the dungeons for intruders. No-one must get in or out!a aAt once, High Guardian,a Banjax replied, and the air resounded with the tramp of the Guardiansa heavy boots on the wooden stairs.

The Most High Guardian looked back up at the Skyraider. The sky ship had pulled away from Midnightas Spike at last, and seemed to be heading round in a great circle. aSo you think youave tricked the Most High Guardian of Night, do you?a he hissed.

Twig gripped the main-sail lever grimly. With the flight-rock irreparably weakened, he was dependent on the great, tattered sail for lift. Slowly, carefully, battling against treacherous draughts of misty air, he brought the Skyraider round to the east side of the tower and began the long, perilous descent.

Wumeru cried out. aWuh-wuh. Roo-wuh-ook!a Peering down, Twig saw Rook standing on a jutting gantry, a third of the way down, together with a Twig gasped. Could that be him? Could that stooped, grey-haired figure truly be his apprentice, Cowlquape? He looked so frail, so fragile a" so old.