"We had a deal, right, so I went round to his flat and he wasn't there, and I've been waiting two whole f.u.c.king hours here, and now I have to go down the social and sign on. When you see him, tell him I was looking for him," the grebo said, and lurched off without giving his name.

That evening, after he'd closed up his shop, Martin made a detour on the way home, to call on Dr. John. He told himself that his friend was probably in the middle of one of his forty-eight hour sleepathons, but there was no harm checking. Just in case. He leaned on Dr. John's doorbell for five minutes, listening to it trill two floors above him, then went down the whitewashed steps and rang the bell of the private members club in the bas.e.m.e.nt. It was owned by Dr. John's landlord, Mr. Mavros, an after-hours drinking spot featuring sticky purple s.h.a.gpile and red leatherette booths. Martin had worked behind its bar last year, when he'd been sc.r.a.ping together enough seed money for his record shop.

"I hope this doesn't mean trouble for me," Mr. Mavros said, after he had handed over the key to Dr. John's flat.

"He's ill," Martin lied. "I said I'd stop by and see if he needed anything. Soup or aspirin or whatever."

"He look ill when I see him," Mr. Mavros said. He was a thin, consumptive man with no hair on his head except for a splendid pair of thick black eyebrows. He wore red braces over his immaculate white shirt, and as usual a small cigar was plugged into the corner of his mouth. "He come back from somewhere when I was locking up this place, two o'clock in the morning. I say h.e.l.lo and he look straight past me. Into the distance, like he see something that isn't there. I know he drink, he smoke dope, but this was different. You tell him, Martin, if he start on the hard drugs, if he cause me trouble, that's it, I throw him out."

The door to Dr. John's tiny flat stood ajar. The bed-sitting room was hot and stale. Sunlight burned at the edges of the drawn curtains. The bed was piled with cushions and dirty clothes; the floor was strewn with clothes and broken-backed paperbacks, unsleeved records and record sleeves, empty cans and bottles, tin-foil takeaway cartons, and yellowing newspapers. In the filthy little kitchen, the tap was running over a stack of unwashed dishes and pots. Martin turned it off, heard something splash somewhere else in the flat. He called out, felt a jolt of nerves when there was another splash.

The bathroom was a windowless cubbyhole just big enough for bath, bog and wash-basin. The light was off, and it smelt like the seal pool in the zoo. The bath was brimful, and in the semi-darkness Martin could see a shape under the shivering surface of the water.

"John?"

A pale hand lifted like a lily; water cascaded over the edge of the bath. Martin jerked the light cord with a convulsive movement and in the sudden harsh glare of the unshielded bulb the boy in the bath-fully clothed, in the same brown, chalkstripe waistcoat he'd been wearing at the Free Festival-sat bolt upright, eyes wide, water running out of his nose and mouth.

Martin helped the boy out of the bath and got him onto the bed, but he wouldn't answer any of Martin's questions about Dr. John, and quickly fell into something deeper than sleep. He breathed with his mouth open, making a rasping gurgle, and didn't stir when Martin went through his pockets, finding nothing but a couple of pound notes wadded together in a knot of papier-mache. Martin suddenly found that he couldn't bear to stay a moment longer with this unquiet sleeper in the hot, claustrophobic flat, and fled into the late-afternoon sunlight and the diesel dust and ordinary noise of traffic.

He sat on the bench beside a telephone box on the other side of the road and thought about his options. If he told Mr. Mavros what he'd found, the landlord would probably throw out the boy and change the lock on the door. And if he went to the police, they'd probably make a note of Dr. John's disappearance and forget all about it. He could always walk away, of course, but Dr. John was a friend who had helped him out of a tight spot, and he had a vague but nagging sense of duty.

Sooner or later, he thought, Dr. John would turn up, or the boy would wake up and slope off to wherever Dr. John was hanging out. All he had to do was wait. How hard could that be? He went around the corner, bought a parcel of fish and chips and a can of c.o.ke, and returned to the bench. The blue sky darkened and the air grew hotter and thicker. A police car slowed as it went past and the driver took a lingering look at Martin, who had to suppress an impulse to wave when the car came back in the other direction ten minutes later. The streetlights flickered on. A little later, Mr. Mavros switched on the light over the door of his club, illuminating the board painted with its faintly sinister motto: There are no strangers here, only friends who haven't met.

Martin bought another c.o.ke at the fish-and-chip shop, and when he returned to the bench saw something swoop down onto the roofline of the row of houses, joining the half dozen white birds that hadn't been there five minutes ago. They're only gulls, he told himself, there are plenty of gulls in Bristol. But he got the shivers anyway, flashing on the monster that had nearly amputated his fingers, and was about to turn tail and head for home when he saw the boy in the brown waistcoat ambling away down the street.

The boy must have crawled back into the bath before he left Dr. John's flat; he tracked wet footprints that grew smaller and smaller as Martin followed him through the villagey center of Clifton towards the Avon Gorge, walking with a quickening pace as if drawn to some increasingly urgent siren song. By the time they'd reached the gra.s.sy s.p.a.ce in front of Brunel's suspension bridge, Martin was jogging to keep up. The boy walked straight across the road, looking neither right nor left, and plunged into the bushes beside the public lavatories. Martin got up his nerve and followed, found a steep, narrow path, and climbed to the top.

The sky was cloudless and black. The moon, almost full, was setting. The stubby observatory tower that housed a camera obscura shone wanly. Beyond it, the boy and half a dozen other people stood at the rail along the edge of the gorge. Martin skulked behind the thin cover of a clump of laurel bushes. He had the airy feeling that something was about to happen, but didn't have the faintest idea what it would be. One of the giant, arch-pierced stone towers that supported the suspension bridge reared up behind his hiding place, and it seemed to him that the watchers at the rail were staring at the lamp-lit road that ran between bridge's white-painted chains and struts to the other side of the deep narrow gorge.

Martin settled behind the laurels, sipped warm c.o.ke. Gradually, more people drifted across the moonlit gra.s.s to join the little congregation at the rail. A girl in a cotton dress came past Martin's hiding place, so close he could have reached out and touched her bare leg. No one spoke. They stood at the rail and stared at the bridge. They reminded Martin of the gulls on the roof. Whenever he checked his digital watch, cupping his right wrist with his left hand to hide its little light, far less time had pa.s.sed than he had thought.

10:08.

10:32.

10:56.

He must have dozed, because the noise jerked him awake. The people lined up along the edge of the drop were chanting, a slow liturgical dirge of nonsense words rich in consonants. They bent against the rail, their arms outstretched, swaying like sea anemones in a current, reaching towards the bridge. Martin turned, and saw that two shadowy figures were walking along the road to the mid-point of the bridge, where the downcurving arcs of white-painted suspension chains met. One was a man, the other the girl in the white dress. She embraced her companion for a moment, and then he broke away and clambered over the rail and without hesitation or ceremony stepped out into thin air and plummeted into darkness.

Martin stood up, his heart beating lightly and quickly, his whole skin tingling, and thought that he saw a brief green flash in the river directly below the bridge, a moment of heat lightning. The girl was walking along the bridge towards the other side of the gorge; the people at the rail were beginning to drift away, each moving in a different direction.

One of them had a cloud of bushy hair, and walked with a distinct list.

Martin chased after him, stumbling in the dark, making far too much noise as he dodged from one clump of bushes to the next, at last daring to cut across his path and grab him by the shoulders and turn him around. Dr. John tried to twist away, like a freshly-caught fish flopping in a trawlerman's grasp. Martin held on and at last his friend quietened and stood still, his gaze fixed on something a thousand miles beyond Martin's left shoulder.

"Let's get out of this," Martin said, and took hold of Dr. John's right arm above the elbow and steered him through the streets of Clifton to Worcester Terrace. There was another brief struggle after Martin had opened the front door, but then Dr. John quietened again and allowed himself to be led up the four flights of stairs to Martin's flat. He stood in a kind of dazed slouch, blinking slowly in the bright light of the kitchen while Martin made coffee, taking no notice of the mug that Martin tried to put it in his hand.

Martin leaned against the counter by the sink and sipped his own coffee and asked Dr. John where he'd been, what had happened to him, what the f.u.c.k had just happened on the bridge.

"Someone jumped. I saw it. He climbed over the rail and let go."

Dr. John didn't even blink. Martin had to step hard on the impulse to slap him silly.

"It's something to do with the pill, isn't it? The green pill, and the girl who gave it to you. Don't try to deny it, I saw her with whoever it was that jumped."

Dr. John stood still and silent, face slack, shoulders slumped. Or not entirely still-one hand was slowly and slyly creeping towards the breast pocket of his denim jacket. Martin knocked it away and reached inside the pocket and pulled out the green pill and held it in front of Dr. John's face.

"What is this s.h.i.t? What does it do to you?"

Dr. John's eyes tracked the pill as Martin moved it to and fro; his hand limply pawed the air.

"Don't be pathetic," Martin said. He thrust the pill into the pocket of his jeans and steered Dr. John into the living room and put him to bed on the sofa. Then he went out to the phone box at the end of the road, dialed 999 and told the operator that he'd seen someone jump from the Clifton Suspension Bridge, and hung up when she asked for his name.

When Martin went into the living room the next morning, Dr. John was fast asleep, curled into the back of the sofa and drooling into the cushion he was using as a pillow. After Martin had shaken him awake and poured a cup of tea into him, he claimed not to remember anything about the last night, saying, "Man, I was definitely out of my head."

"You don't know the half of it."

They were sitting at the kitchen table. Dr. John drank a mug of tea and devoured three slices of white bread smeared with b.u.t.ter and sprinkled with brown sugar while Martin told him about the boy in the bath, the people lined up at the railing above the Avon Gorge, and the girl who had escorted the man to the midpoint of the bridge, how she'd embraced him, how he'd stepped into thin air. Dr. John wore a funny little smile, as if he knew the secret that would make sense of everything, but when Martin had finished he shrugged and said, "People jump off the bridge all the time. They queue up to jump off. The police have to comb pieces of them out of the trees, sc.r.a.pe them off the road, dig them out of the mud . . . " He patted his pockets. "Got any f.a.gs?"

Martin found a packet his girlfriend had left behind.

"Silk Cut? They're not real cigarettes," Dr. John said, but tore off the filter off one and lit it and sat back and blew smoke at the ceiling.

Martin was tired of trying to crack Dr. John's bulls.h.i.t insouciance, but decided to give it one more try. He leaned across the table and said as forcefully as he could, "Someone jumped off the bridge. I saw it."

"I believe you, man," Dr. John said, still smiling that sly little smile "If you don't remember anything at all, you really were out of your head. And I thought there wasn't a pill or powder you couldn't handle."

"It isn't that I don't remember anything, man. I just don't remember any of the s.h.i.t you saw. That was just the pattern on the veil that hides the true reality of things. That hides what's really going on."

"So what was really going on?"

"It's kind of hard to explain."

"I want to understand."

"Are you worried about me, man? I'm touched."

"I saw someone throw himself off the suspension bridge. The girl who gave you that pill, the one in the white dress, was right there with him when he jumped. I think that guy got high on whatever it is she's peddling, just like you did, and she persuaded him to jump. I think she killed him. That's what I saw. How about you?"

Dr. John thought for a few moments. "What you have to understand is that the green s.h.i.t doesn't do anything but put you in the right frame of mind. It takes you to the beach, and after that it's up to you. You have to wade out into the sea and give yourself up to it of your own free will. And if you can do that, the sea takes you right through the bottom of the world into this s.p.a.ce that's deeper and darker than anywhere you've ever been. The womb of the world, the place where rock and water and air and everything else came from."

He developed a thousand yard stare for a moment, then shook himself and smiled around the cigarette, showing his broken tooth.

"It's very dark and quiet, but it isn't lonely. It's like the floor of the collective unconscious. Not in the Jungian sense, but something deeper and darker than that. You can lose yourself in it forever. You dissolve. This is hard, trying to explain how it is to someone who doesn't believe a word of it, but haven't you ever had that feeling when everything inside you and everything outside you, everything in the whole wide world, lines up perfectly, just for a moment? I remember when I was a kid, this one day in summer. Hot as it is now, but everything lush and green. Cow parsley and nettles growing taller than me along the edges of the road on the way up to the common. Farmers turned cows and sheep out to graze there, and the gra.s.s was short and wiry, and warm beneath you when you lay down, and the sun was a warm red weight on your closed eyelids. You lay there and felt the whole world holding you to itself, and you heard a lark singing somewhere above you in the sunlight and the warm wind. You couldn't see it, but it was singing its heart out above you, and everything dissolved into this one moment of pure happiness. You know what I'm saying? Well, if you take that feeling and make it a thousand times more intense and stretched that one moment out to infinity, it would be a little like where I went."

"Except that you were high. It didn't really happen, you only thought it did."

Dr. John looked straight at Martin, smiling that sly smile, and said, "You don't know what I'm talking about, do you? You're just a tourist, man. A day tripper. You might have ventured onto the beach a couple of times, you might even have dipped a toe into the sea, but that's as far as you've ever dared to go. Because as far as you're concerned, drugs are recreational. Something you do for fun."

Martin felt a sharp flare of anger. He'd seen something awful, he believed that he had risked his life to rescue Dr. John, and his only reward was scorn and derision. "If you want to f.u.c.k yourself up," he said, "do a proper job and score some heroin from that guy who works for those gangsters who beat you up."

"I found something better," Dr. John said. "We all did. Something we didn't know we needed until we found it. You don't need it, man. That's why she turned you down. Even if you got hold of some of her stuff and got off on it, you wouldn't be able to take the next step. You wouldn't be able to surrender yourself. But we knew where it would take us before we'd even seen it. We ached for it. It's our Platonic ideal, man, the missing part we've been searching for all our lives."

"One of your little gang killed himself last night. He threw himself off the suspension bridge, right in front of my eyes. He committed suicide. Is that what you want?"

"Suicide? Is that what you think you saw?"

Dr. John looked straight at Martin again. For a moment, Martin glimpsed the worm of self-loathing that writhed behind the mask of his fatuous smile and flippant manner. He looked away, no longer angry, but embarra.s.sed at having glimpsed something more intimate than mere nakedness.

"Something wants our worship," Dr. John said, "and we want oblivion. It isn't hard to understand. It's a very simple deal."

"If you take another of those pills, you could be the next one off that bridge," Martin said.

Dr. John stood up. "You have your nice little flat, man, and your nice little shop and your nice little gigs with loser pub rock bands. You have a nice little life, man. You've found your niche, and you cling to it like a limpet. Good for you. The only problem is, you can't understand why other people don't want to be like you."

Martin stood up too. "Stay here. Crash out as long as you like. Get your head straight."

Dr. John shook his head. "My friends are waiting for me."

"Don't go back to the river," Martin said, but Dr. John was already out of the door and clumping away downstairs.

Martin shut up shop early that afternoon and took a walk up to the observatory. Children ran about in the sweltering heat, watched by indulgent parents. People were sunbathing on suncrisped gra.s.s. There was a queue at the ice-cream stall by the entrance to the observatory tower. Someone was flying a kite. It was all horribly normal, but Martin was possessed by a restless sense that something bad was going to happen. As if a thunderstorm hung just beyond the horizon, waiting for the right wind to blow it his way. As if the world was suddenly all eggsh.e.l.l above a nightmare void. He drifted back through Clifton village and ended up in the Coronation Tap and drank five pints of Directors and ate one of the pub's infamous mystery pies, and at closing time walked back to the suspension bridge and thrashed through bushes to the top of the rise.

There they were, leaning at the rail in the warm half-dark, staring into the abyss.

None of them so much as glanced at Martin as, his heart beating quickly and lightly, his whole skin tingling airily, he walked across the gra.s.s. They leaned at the rail and stared with intense impa.s.sivity at the gorge and the floodlit bow of the suspension bridge. The two women on either side of Dr. John didn't even blink when Martin tried to pull him away, tugging one arm and then the other, trying to prise his grip from the rail, finally getting him in a bear-hug and hauling as hard as he could. As they staggered backwards, a gull skimmed out of the dusky air and bombed them with a pint of hot wet bird s.h.i.t. It stank like thousand-year-old fish doused in ammonia, and stung like battery acid when it ran into Martin's eyes. Half-blind, gasping, he let go of Dr. John and tried to wipe the stuff from his eyes and face, and another gull swooped past, spattering him with a fresh load, clipping him with the edge of a wing. Martin sat down hard, saw more gulls circling in the dark air, one of them much bigger than the rest. It dipped down and swooped towards him, its wings lifted in a V-shape. His nerve gave out then, and he scrambled to his feet and ran, had almost gained the shelter of the bushes when the bird hit him from behind, ripping its claws across his scalp and knocking him down. He was crawling towards the bushes, blinded by blood and bird s.h.i.t, when another gull smashed into him, and the world swung around and flew away like a stone on the end of a string.

When Martin came to, the swollen disc of the full moon was setting beyond the trees on the other side of the gorge. Its cold light filled his eyes. The person standing over him was a shadow against it, reaching down, clasping his hand and helping him sit up.

"Christ," Simon Cowley said. "They really worked you over."

Martin's face and hair were caked in blood and gull s.h.i.t. His skin burned and his eyes were swollen half-shut. He gingerly touched the deep lacerations in his scalp, winced, and took his hand away.

"Gulls," he said.

"Vicious little f.u.c.kers, aren't they? Especially the big one."

"What do you know about it? And what are you doing here?"

"I came here after your hippy friend spiked my beer. I woke up from a horrible dream and found myself standing at the rail over there, in the middle of a whole bunch of sleepwalkers. I've been coming back every night since. And every night someone has gone over the bridge into the river." Simon's long blond hair was unwashed and he stank of sweat and sickness. His eyes were black holes in his pale face. A khaki satchel-an old gas mask carrier-hung from his shoulder. He looked around and said in a hoa.r.s.e whisper, "I think there's something in the river. I think it swam in from the sea on the last high tide, it's been trapped here ever since because the drought lowered the level of the river. It's been living on what they give it."

"They worship it," Martin said, remembering Dr. John's ravings.

"I think it draws them here and makes them jump off the suspension bridge. I think it eats them," Simon said, "because no one has reported finding any bodies. You'd think, after at least three people jumped off the bridge in as many days, one of them would have washed up. I went down there yesterday in daylight, and took a good look around. Nothing. It devours them. Snaps them up whole."

Martin got to his feet. Heavy black pain rolled inside his skull. His eyes were on fire and his lacerations felt like a crown of thorns. He said, "We should call the police."

"You saw what was down there. I know you did because I saw you here last night."

"I saw something. I don't know what it was."

"You think the police can do anything about something like this?" Simon c.o.c.ked his head. "You hear that?"

"I hear it."

People were chanting, somewhere below the edge of the gorge.

"It's beginning," Simon said.

"What's beginning?"

"You can help me or stay here, I don't care," Simon said, and ran towards the path that led down the face of the gorge.

Martin chased after him. Everything was black and white in the moonlight. Bleached trees and boulders and slabs of rock loomed out of their own shadows. The day's heat beat up from bare rock. The black air was oven-baked. Martin sweated through his T-shirt and jeans. His feet slipped on sweat inside his Doc Martens. Sweat stung his swollen eyes, his lacerated scalp. He caught up with Simon at the beginning of a steep smooth chute of limestone that had been polished by generations of kids using it as a slide. At the foot of the gorge, people were crossing the road, shambling towards the girl in the white dress, who stood at the rail at the edge of the river. A pa.s.sing car sounded its horn, swerved past them.

Simon didn't look around when Martin reached him. He said, "You see her? She's the locus of infection. She's been missing for two weeks, did you know that? I did some research, looked at back copies of the Evening Post for anything about people jumping from the bridge, and there she was. I think she jumped off the bridge and the thing in the river took her and changed her and sent her out to bring it food."

Below, people were climbing over the guard rail at the edge of the road. The river shone like a black silk ribbon between its wide banks of mud. White flakes-gulls-floated above one spot.

"We have to stop it right now," Simon said. "It's high tide tonight. I think it wants to take them all before it goes back to sea."

"All right. How are we going to stop it?"

"I'm going to blow it up. I stole two sticks of dynamite from work. Taped them together with a waterproof fuse. You distract them and I throw the dynamite and we run."

"Distract them?"

People were slogging across the mud towards the gyre of gulls. They had started up their chant again.

"Shout at them," Simon said. "Throw rocks. Try to take back your hippy friend, like you did just now. Whatever you like, as long as you get them to chase you. Then I'll chuck the dynamite in the river, right at the spot under those gulls."

"Suppose they won't chase me?"

In the high-contrast glare of the moonlight, Simon's grin made his face look like a skull. "I'll chuck it in anyway."

"You're crazy. You'll kill them all."

"They're already dead," Simon said, and turned away. Martin grabbed the canvas satchel, but Simon caught the strap as it slid past his wrist. For a moment, they were perfectly balanced, the satchel stretched between them; then a gull swooped out of the black air. Simon ducked, staggered, put his foot down on thin air and fell backwards. Martin sat down heavily, the canvas satchel in his lap, heard a rolling crackle as Simon crashed away through bushes, saw the pale shape of the gull fall away as it plummeted after him.

Martin got to his feet and slung the satchel over his shoulder and went on down the path, fetched up breathless at the bottom, his headache pounding like a black strobe. An articulated lorry went past in a glare of headlights and a roar of hot wind and dust. Martin ran across the road, clambered over the guardrail, and dropped to a swale of gra.s.sy mud, breaking through a dry crust and sinking up to his knees.

He levered himself out and stumbled forwards. He could hear the tide running in the river, smell its rotten salty stink. Inky figures stood along the edge of the black water on either side of the girl's pale shadow. Gulls swooped around them. Their hands were raised above their heads and they were chanting their nonsense syllables.

Ia! Ia! Ia-R'lyeh!

There was a sudden splashing as hundreds of fish leapt out of the water, shards of silver flipping and thrashing around the line of men and women. Martin ran down a shallow breast of mud, shouting Dr. John's name, and something huge breached the river. Light beat up from it in complex l.a.b.i.al folds, rotten, green, alive. Gulls swirled through the light and flared and winked out. Blazing fault lines shot across the mud in every direction; fish exploded in showers of scales and blood.

The people were perfectly silhouetted against the green glare. They were still chanting.