'The first floor is on fire,' said Mr Cox. He held out his palm and a vesperi placed a flintlock pistol in it. 'Ivan, you are more trouble than you are worth and now I am going to kill you.'

Miss DeGroot let out a throttled mewl. The fingers of her right hand were elongating like warm wax. The vesperi nearest to her began backing away. She tried to make a fist, gasping with the effort, but her fingers swayed limply.

'Peter! What's happening to me?' She glared at her hand, straining to turn it palm upwards. She gritted her teeth. Slowly, slowly, her long, creamy digits began to retract, like lengths of saliva drawn back into the mouth. Miss DeGroot's cheeks coloured. Her hand was almost restored.

She grunted. Her arm fell and burst on the hearth rug.

Miss DeGroot stood staring at the mess of pink-white fluid. It ran from the stump of her shoulder, dripping down the skirts of her evening gown and spread in a feathering mane across the hearth. She vomited down her front. She looked at Stokeham helplessly, her chin glistening.

Delphine heard a clatter from off to her right. She glanced across and Mother had let the jam tin drop to the foot of the piano stool. Mother kicked the improvised grenade and it slid towards Delphine like a puck. It caught a nick in the floor and flipped onto its side, rolling under Delphine's chair.

Stokeham had been approaching the fireplace and wheeled round at the noise.

'What was that?' said Cox.

The remaining sixteen or so vesperi drew their daggers. Delphine slid her ankles together, trying to hide the grenade, but the action drew Stokeham's attention. Cox set down his pipe and advanced on her.

'What have you got there?'

'Don't let him have it!' said Mother.

'Stop her!' said Cox. 'Bring whatever it is to me.'

Four vesperi converged on her. Delphine rocked forward onto her feet, lifting the chair off the floor. One vesperi grabbed the sleeve of her cardigan. A second reached for the jam tin. Mr Cox was bearing down on her. She twisted, catching the second vesperi in the forehead with the leg of the chair, then toe-punted the jam tin at the fireplace. The old condensed milk can rolled, bootlace fuse whipping round and round like the leg of a clockwork spider. Miss DeGroot blinked dumbly as it spun past. Calmly crouching by the fire, Stokeham reached out to stop it. The tin clipped the lip of the hearth. It bounced over Stokeham's waiting glove and into the flames.

A vesperi tackled Delphine's knees and she let herself fall, yelling: 'Everyone down!'

Out of the corner of her eye, she saw Stokeham stooped over the fireplace, thrusting a leather gauntlet into the glow. Cox screamed.

Everything went white.

In the underground chamber, Henry lay bleeding from the mouth. The bat-monster pressed a bony knee into his chest and raised the cudgel for the coup de grace.

Its gristly face crumpled. It dropped the cudgel. It clutched its gut. Henry grabbed the unloaded shotgun and drove it up into the valet's fangs with the heel of his palm. A crack echoed off the dripping stalactites and the beast staggered back, slobbering blood.

Henry grabbed a cartridge from the floor and slid it into his shotgun. Before he could close the breech, the lone remaining vesperi was retreating. He traced it with the gun as it scrambled for the exit, let it go. The valet was doubled over, spitting out teeth. Henry planted the gun stock on the floor and rose unsteadily, grunting. His kneecaps felt as if someone had driven steel pegs through them.

He brought the muzzle to bear on his opponent.

'A word about the terms of your surrender.'

From the balcony of the Great Hall, Gideon watched as the front doors opened and the Devil strode in. His curving horns were unmistakable. A dozen angels marched behind Old Nick in perfect lockstep.

It was just like Arthur had promised.

The bowstring was taut beneath Gideon's fingers, the firebombs snug against his belly. He had recovered the righteous weapon, and now Satan stood in the courtyard waiting to be absolved. The chequered floor marked out the distance in neat, stark squares. Black and white. Death and rebirth. An end to all pain. A beginning.

Gideon stepped from cover and let fly.

Delphine heard the windows shatter. A moment later she felt the force of the blast against her closed eyelids.

She tried to look up but the grenade must have blown the fire out and toppled the lamps because the banqueting hall was black. She thought she saw the crystal pendants of the dead chandelier, scintillating like sardines in the darkness, then a vesperi was on top of her, pressing the flat of its dagger to her windpipe. Its dark brown eyes scanned her face, pink bootlace tongue whipping over the grey stumps of fangs. It lifted its head; its nose-leaf flared as it called: Rrrrrik-ik-ik-ik. Rrrrrik-ik-ik-ik.

Across the room, calls bubbled in reply. A clawed toe dug into her ribs. A necklace of twine hung from the skinwing's throat, threaded with pink shells that brushed her chin as it breathed. Its breath smelt of burning hair. The fallen chair creaked beneath their combined weight.

She heard the scuffling of taloned vesperi feet converging on the hearth. Delphine concentrated on a white fleck of foam in the corner of the vesperi's mouth. It reminded her of the foam in Mr Kung's eyes on the beach. He had died in a hospital bed, alone and very far from home. Delphine knew she might die now, and the thought of Mother, sitting or lying a few yards away, was comforting. The vesperi's face became blurry, and she had to blink to make it clear.

An unearthly calm had settled over the room. This was what soldiers meant by the dread when the Hun's artillery went quiet. You expected it to feel like a relief, but then you began to wonder: why has it stopped? What are they planning? And you listened for clues but your ears were ringing from the noise and there was nothing but the sense of something terrible and lethal and huge, silently preparing to administer the masterstroke.

The creature kept grimacing, drilling a finger in its earholes. The noise of the explosion seemed to have affected its hearing. It looked back over its shoulder. Downy white hairs filled the hollow of its ear.

She thought about trying to roll out from beneath it while it was distracted. The blade was still at her windpipe, not cutting restraining. The vesperi on top of her pip-pipped something. A reply echoed back through the darkness, but the creature didn't seem to hear. It returned its attention to Delphine.

Something cracked against its skull. The skinwing hit the floor and skidded a couple of feet on its jowl.

'Now!' Professor Carmichael stood over her, grasping the huge ceremonial warhammer. He had ripped it from its wall mounts a steel bracket swung from the gemmed handle as he turned to face the room. 'Everybody! Fight!' He knelt at Delphine's side. 'Hold still. I'll cut you loose.' He picked up the vesperi's dropped dagger. He turned left and slashed: 'Ungh.' She heard the knife rasp through fabric and flesh. A body clattered to the floor and the Professor stabbed it once, pfft, the creature expiring with a sigh.

He leant over her and began sawing at the rope.

'Where's Peter?' said Delphine.

'You mean that bastard in the mask? Dead.'

'And Cox?'

'I don't know.'

She could hear footsteps, chairs scraping, cries. She heard a male exclamation, a thump, a scream. The Professor's knife dug into the trench between her wrists, chewing through the ropes. Her bonds slackened then sloughed off. She slapped her palms to the floor and sprang to her feet just in time to see three javelin-wielding vesperi surrounding her and the Professor. Standoffs were taking place all round the room. Her eyes were adjusting. She saw shifting outlines, havoc.

The Professor pressed Delphine's crab hook into her palm.

'Give the buggers Hell.'

He lifted the great silver warhammer above his head like some figure from Norse legend. The three vesperi spread out, attempting a flanking manoeuvre. One was whistling a tremulous, intermittent tone, like someone tuning a wireless.

'Stick close to me. Yah!' He stamped and all three vesperi recoiled, furling their wings and hopping out of range. Delphine brandished her hook and tried to look menacing. The creature nearest her seemed to sense her reluctance; it advanced, spreading its wings till it was wide as it was tall. She backed away. The creature closed in.

'Grrrah!' The Professor swung the hammer in a broad arc, missing all three vesperi but driving them back. The weight of the huge gemmed head pulled him off-balance and he stumbled. Seeing its chance, one of the creatures drove at his exposed flank with its javelin raised, but the stumble was a feint and he brought the hammer's pommel nut crashing back into the skinwing's temple. As the creature went down its neighbour jabbed at the Professor's thigh; he parried with the hammer shaft then brought his knee up under the javelin, cracking his opponent's jaw. The creature squawked and he laid it flat with a forehand stroke. The final vesperi, the one which had been cornering Delphine, hesitated. The Professor roared. It fled.

He looked at Delphine. He was panting.

'In one piece?'

She nodded.

'It seems,' he said, 'today . . . you are to put . . . some of your theories . . . on warfare . . . into practice.'

Across the room, the remaining vesperi had surrounded Alice, Mrs Hagstrom and another male guest. The hostages stood marooned on the sofa, arms tied behind their backs. Mrs Hagstrom was kicking and snorting. A vesperi slashed at her and she gasped. The Professor wiped his mouth on his sleeve and charged.

Before she knew what she was doing, Delphine had joined him. The creatures turned round, click-shrieking. She raised her crab hook. The vesperi raised their curved daggers in response. Professor Carmichael bellowed. At the edge of the pack, a skinwing flinched. It bolted. Delphine screamed. The other vesperi glanced from their knives to each another. They held. The Professor raised the warhammer to strike, his tawny hair sticking out in peaks of clotting blood.

The vesperi scattered.

Delphine watched them go. She ran to where Mother lay face down.

'Delphine?' Mother had a bruise under her eye the size of a mandarin segment.

'Hold on. You're nearly free.' Delphine sawed through the ropes binding Mother's wrists. She offered Mother her hand. Mother looked at it, disorientated. She closed her long cold fingers around Delphine's palm. Delphine helped her up.

Delphine's eyes were adjusting. Her head felt swimmy. She could make out Stokeham's crumpled body in front of the blown-out fire. It looked as if the masked figure was sleeping, then Delphine tilted her head and moonlight caught the ruptured sternum, the glistering mush. A leather-gauntleted hand lay open, grasping nothing.

A few yards away, Mr Cox lay prone, chestnut locks spreading from his scalp in a starburst, legs splayed beneath his brilliant blue rump. It seemed the servant could not survive without the master.

Delphine and Mother joined the group led by Professor Carmichael. Mr Wightman stepped aside to reveal Mrs Hagstrom lying on her flank, clutching a long deep slit in her arm. Dark blood bubbled up between her fingers. Her skin was tight and marbled.

'Come on now, my dear.' The Professor rested a hand on her shoulder. 'Up you get. It's closing time.' With Mother's help he lifted Mrs Hagstrom to a sitting position.

Mrs Hagstrom looked at Delphine. One of her eyes was flooded with red.

'Sorry I didn't believe you,' she said.

Through the ringing in her ears, Delphine thought she heard a noise. It solidified into a word: 'Wait.'

The voice was dry, tremulous. It was coming from the middle of the room. Delphine turned.

Miss DeGroot was trying to stand. Her burst arm had hardened into thick strands, stretching from her shoulder to the floor in a fleshy cobweb. Ropes of tendon and scar tissue tightened as she rose, dragging up sections of rug.

'Wait,' she said. Steam twisted from a chunk of horseshoe lodged in her eye socket. She focused on the ruin of her arm. Parts of it had fused with the floor. The sinews went taut. She exhaled and they fell slack.

Reg Gillow started coming round. He moaned, went rigid in the armchair. Professor Carmichael ran over and slit his bonds. One of his arms hung by his side. His other hand went to his eye. He doubled-up, howling.

'Reggie!' Alice dashed across the banqueting hall and hugged him. Reggie was gibbering, shrieking and clutching his face. 'What's wrong? What happened to you? Reggie, tell me, please!'

'No, no, no.' Mr Wightman was dazedly making his way towards the doors. 'I've had enough of this madness.'

Delphine looked from Reggie, to Miss DeGroot, to the door. The vesperi should have returned by now.

'We must go.' The speaker was Propp. He had managed to stand. His wrists were still tied behind his back. His waistcoat was torn, face fruiting with bruises.

'Wait!' Miss DeGroot tried to walk towards them but the remnants of her arm tethered her in place. She tugged and twisted but only succeeded in rucking the hearth rug. She swore. She was weeping from her remaining eye.

Miss DeGroot spun to face Delphine.

'Please,' she said, reaching out with her human hand. 'Don't leave me.'

Small fires guttered around Gideon and the Devil.

They faced each other on the great chessboard. The angels were dead. The Devil stood with His horns low, two arrow shafts sticking from the hump of muscle behind His neck. He breathed in wounded snorts. He could not raise His head.

Gideon held a curved angel dagger, serrated on its inner edge. He pressed the pommel to his crashing heart.

The Devil charged.

Delphine fought against her shuddering hands and the sickness rising in her throat, and forced herself to meet Miss DeGroot's gaze.

Miss DeGroot took a long breath.

'I don't . . . feel anything.' She looked back at the flesh trailing from her shoulder and seemed to experience a kind of vertigo. 'I can feel the shape of it, but . . . there's no pain.' She squinted the raw cauterised flesh of her eye around the shrapnel.

'Mmm.' Propp stepped forward. He nodded towards Reggie, who moaned as Alice cradled his head and wept. 'He feels your pain now. It cannot be undone.'

Miss DeGroot swivelled to face him, melted arm plaiting round on itself. 'This is your fault.'

'Please, noble friend . . . '

Miss DeGroot closed her eyes and shook her head.

'No, Ivan. No more of this . . . of this Mr Ghandi schtick. I can't bear it.' She sighed and massaged her hairline with her fingertips. She glanced at Delphine. 'Please. I need some help.'

Delphine stared at her.

'Look,' said Miss DeGroot, 'I never meant for Titus to get hurt. I was just trying to reunite a daughter with her father.' She took a step towards Delphine and the wet ropes tensed, jerking her shoulder back. 'The cancer was eating me alive. Ivan wouldn't tell us how to beat it. Don't you see? I had. No. Choice.'

There was a flurry of footsteps and a bang from the double doors. Delphine turned. A quick inventory of the room revealed that Mr Wightman had made his escape.

'Hey!' Miss DeGroot cast about. 'Who was that? What are you doing?'

Professor Carmichael cupped his hands to his mouth. 'Everyone run!'

Delphine froze, unsure of which way to turn.

'Please!' Miss DeGroot's face passed through confusion and fury, before settling on desperation. She grasped for Delphine with her normal hand, her bare feet slipping on the hardwood. 'Don't leave me!' Her fingers opened and closed on air.

Delphine glanced around for Mother, saw her tugging at Alice's elbow, trying to get the girl to stand. Alice made a small, choked sound. She had Reggie's blood and vomit down her dress.

Delphine looked back at Miss DeGroot. She was kicking and straining against the tendrils binding her to the floor, but they were thick as oak roots. A vein stood out on Miss DeGroot's forehead. She turned to Delphine, her single pupil shrunken with fear.

'Wait,' she said.

Everyone else was moving towards the east doors. Delphine hesitated.

'Wait!' said Miss DeGroot. She swallowed. She clutched at the air between them. 'Why won't you wait for me?'

Delphine took an involuntary step back.

Cables of skin and muscle stretched taut, elongating as Miss DeGroot pulled against them. Reggie screamed. Where they met the floor, they had begun to secrete a black, oily fluid. She had blood on her teeth. She reached for Delphine. 'Come . . . here . . . '

Delphine could not move. She was paralysed by the motion of Miss DeGroot's clammy human fingers. The air was full of a warm stink like brewer's yeast. Miss DeGroot grimaced, bracing her knees.