Less than half an hour after they had left, the squat man returned. He looked around him, he then descended. Then Charlie came back.

  He walked quickly and his shoulders were up.

  Tova gave it a minute, then approached slowly to the top of the stairs, leading down to the laboratory door. She descended quietly. She wiped a window beside the threshold clean. Tova dropped the filthy tissue and put her hands to the glass and looked in.

  One light was on, in the farthest corner of the room. There was no motion. The illumination came from the refrigerated annex: the door was propped open. Tova moved a little to see inside and said clearly and as calmly as she could, “Oh Jesus fucking Christ, Charlie.”

  She could see him sitting, motionless, his back leaning against a bench within the refrigerated chamber.

  He did not look like a person but like a puppet, top-heavy, bad and absurd, because he wore the pig’s head again.

  Tova hammered on the door.

  “Charlie,” she shouted. “I’ll get the cops if you don’t let me in.”

  He was not moving but someone else was. The squat man had been sitting near him on the floor, she realized, and now was rising, shuffling toward her. “Let me in right fucking now,” she said.

  He pushed the door open a slit and started to say something guarded and Tova shoved past him easily and came inside. The man’s face was moist and he smelled. Tova ran to the cold where Charlie sat slumped.

  The skin on the pig’s head was wrinkled and bruisy blue. Charlie’s shoulders were claggy with its half-frozen matter. The cut in its cheek flapped. Loose flesh hung under its sinking eye.

  “Take it off,” she shouted. She cried out in more disgust to see a woman kneeling in the corner, wearing a cow’s cold head.

  Where the thickset man had been sitting was a hacked-off crocodile head. “You can’t come in here like this,” the man said. “This isn’t your business. You can’t do that.”

  He plucked at her as she pulled at the pig’s head Charlie wore. She slapped the man’s hand away.

  “Help me or fuck off,” she said.

  “You can’t just yank,” he said. He had swellings on his wet face. He hesitated a moment then took hold of the pig’s flesh. “Look,” he said. “You have to—” He ran a hand gently around the neck hole, pushed his fingers into the dead mouth, making Charlie moan. “OK.”

  They pulled the head off together and tipped it away. It hit the floor with a moist thump. Tova kicked it and it rolled unevenly and she saw the black tentacles on its inside, writhing on the swollen lump of its tongue, clutching for Charlie’s face. They twitched sluggishly in the chill.

  Charlie blinked, slick with mucal coating. She reeled from the smell of him. His chin looked gnawed. Swellings wept on his skin.

  “Tova,” he said. He focused slowly. “Tova.”

  “Charlie,” she said. She almost cried. “Look at you … What are you doing?”

  “Tova.” He wobbled slowly to his feet. “What are you doing?” His voice was thick as if he was drunk. “This is, you know I have to—”

  “Seriously, Charlie?” she said. She shivered and watched her breath. “Don’t fucking talk shit to me. I know what you’re doing. This isn’t your treatment, look at you.”

  “You don’t even know,” he said. “What you’re talking about.”

  “Christ, you can hardly talk. What are you doing? How’d you get in, did you steal the keys to this place? Did he?” She pointed to the man who had worn the crocodile. The cow-woman did not move.

  Charlie left the cold chamber and went to a basin and turned on a tap. He bent to it. He did not drink, but he stuck out his tongue and closed his eyes as the water ran over it.

  “I’m going to be sick,” Tova said. The marks on his face were already deflating, but she could see them still raw in his mouth. His tongue was gray and dimpled, looked almost moldy.

  Charlie opened his eyes and they widened when he saw the pig’s head lying on its side.

  When Tova brought out her phone, Charlie came back to her and knocked it out of her hand. He stared at her, startled with guilt. The other man picked it up and returned it to her but it was broken. Charlie ran his hands over the inside of the pig mask.

  “You have to go,” the crocodile man said to Tova.

  “You need help,” she said.

  “It ain’t like that,” he said. He pushed her gently toward the door.

  “It is, though,” she said. “I’m calling the cops.”

  “If you do that,” he said, “they’ll come here and it’ll get bad. You want them on us? You want to send him to jail? Look—” He stood with her by the bottom step and tried to formulate something. The muck on his face had dried into foul crust. “Look, I know we can’t … You can’t understand. It’s … we’re fixing this. This is the last time.”

  Of course she didn’t believe him. Despite her threat, nervous of what they might do, she was not ready to set the police on Charlie. She called Derek instead.

  “I don’t know how,” she said, “but they got keys to your lab. No wonder the heads’ve been going off quick, they’re breaking in there and putting them back on while you’re at home. They’ve just been sitting there.” She heard him catch his breath and whisper a curse. “How bad is it?”

  “It’s not—I don’t know,” he said. “The intrusion itself, the feelers? They’re gross but they don’t do you any damage, we don’t think. And it’s not as if everyone in intruded heads goes this way … but it can be addictive. We’ve got some substitutes. I think they gave some to the woman who wore the hippo. It doesn’t normally go on like this, not this long …”

  “Everyone keeps saying that, it doesn’t normally. It has, though. And they’re there right now being junkies. Maybe I should send the police.”

  “Wait. We ought to—look, I’m going to call Dr. Allen, and we’re going to go over. I’m heading over now. She needs to know about this.”

  “Do what you need to and do it fast. I’m not going to watch Charlie fall apart like this.”

  “OK, give me like an hour. I’ll call you back.”

  In fact he called her much before that and shouted down the line at her, his voice querulous and panicky.

  “They’re gone,” he said. “They must’ve taken off as soon as you left. The police are on their way, it’s all gone wrong. Treatment went great with the others but I don’t know what’s happening to these three, I don’t know what’s going on. They took them.”

  “They took the heads?” Tova said.

  “They took the heads.”

  The police went to his flat but Charlie was not there, and it did not seem as if he had come back after going to the hospital. Tova was abruptly sure that she would never hear anything of him again.

  The police asked her if she could shed any light on what Charlie was thinking, what his motivations were. What he might do.

  “We’re concerned for their safety,” the officer said.

  “Me the fuck too,” shouted Tova, “and no I don’t have any idea, that’s the whole point, I don’t know what he’s doing.”

  Tova was wrong. Within two days, she did hear reports of what Charlie was doing. Charlie, and Neil and Simone, the intruded wearers of the pig, crocodile, and cow’s heads.

  A couple in London’s northern suburbs reported seeing three masked, naked people in their garden. Journalists visited the ring of affluent commuter towns and mega-fields surrounding the capital, following more leads.

  A teenager uploaded mobile phone footage onto YouTube. An ugly patch of dead, tooth-white trees by an unkempt field. A broken-down combine harvester rusted by oily mud. The footage wobbled.

  “There,” someone said to the unseen cameraman. “There. Are you blind, man?”

  In the distance, in the fringe of growth, two unclothed men ran from tree to tree. They kept hold of the swaying heads they wore, the bobbing crocodile’s and the pig’s. They were too far to make out well but Tova could see the ug
ly gray-white of Charlie’s skin and the brown of Neil’s, their stiff ridiculous motions. The men ran without enthusiasm, heavy and unconvincing with aimless urgency, as if hiding, then as if hunting, only making themselves more visible. They stopped and stood tall and looked around through the mouths of their meat masks. They dropped to all-fours and disappeared from sight. You could hear the unseen boys who filmed them goading each other to go closer. The footage ended.

  “What are they doing?” Tova said.

  “I don’t know,” said Derek. She could hear him breathing, trying to work out what he was allowed to tell her. “We have theories but—”

  “So tell me theories.”

  “No. I’m sorry, I’m not going to because they’re literally just—we don’t know.”

  “They’re trying to live off the land,” she said.

  “We’re guessing.”

  The police asked her if Charlie had tried to contact her. She laughed at them. “Have you seen what he’s doing?” She did not like the sound of her own voice.

  The papers called the fugitives the Animal Three. They were filmed again by news helicopters, from the bonnetcam of a police car, on CCTV behind warehouses. They shivered with cold in the shallow muddy pond by a fallow field. They picked across a rugby pitch in fading light. A nightwatchman saw Charlie through a fence, taking eggs from the hutch of a pet hen and cracking them one by one through the mouth of the pig, into his own.

  Simone stood in rubbish behind a co-op and stared into the security camera lens. The cow’s head was collapsing on itself, deliquescing on her head. The horns had tipped in toward each other as the crown of the head rotted, as if straining to touch their tips together. The skin was mottled and maggots dropped from it. Simone shuffled toward a gravel pit.

  “This isn’t the fucking Wild West,” Tova said. “We’re talking about an estuary in Essex. Why can’t someone just find them?”

  “You’d be surprised how long a person who knows what they’re doing can hide out,” the liaison officer said. Delingpole was a woman barely older than Tova.

  “Charlie’s in fucking admin …”

  “Well not any more he’s not.” Tova had no response to that. “Look … Thing is, we think we do know where they are. Tova, will you help us?”

  “What do you want me to do?”

  “You’re Charlie’s best friend. You’re the last person—other than those two, if you count them—who spoke to him.”

  “Jesus,” she said. “Are you going to ask me to try to get through to him?”

  Delingpole drove Tova through unpleasant towns and industrial estates in the belt beyond London to acres of scrappy countryside wedged between brownfield sites. There were police cars and an ambulance. Tova saw Dr. Allen and Derek waiting in its back. She waved and Derek responded.

  A slope of dock leaves and nettles, a barn slumped on a hole where it lacked a wall, leaning over the darkness. In the middle of the gap was a chair. Officers in stab-jackets were setting up equipment, muttering into their radios. As Tova approached, she saw several of them report her presence.

  “There?” she said.

  She sat and wrapped her coat around her and shivered while the police team fussed and attached leads to a microphone braced before her. A cold wind raced past her, smelling of tires.

  “So they’re in there?” she said, nodding toward the thickets and tangles of trees at the bottom of the slope she faced. Someone turned on an arc light as if in answer and the green shone.

  “Turn that the fuck off,” someone else shouted, and was obeyed.

  A senior officer squatted in front of Tova.

  “You’ve been briefed then?” he said. “You know what to do?” Tova nodded and the man walked immediately away.

  “You nervous?” said Delingpole.

  “Should I be?” said Tova.

  “No. Break a leg.” Delingpole patted Tova’s shoulder and backed away. “Kill the lights,” Tova heard her say. “We’re ready.”

  One by one the police around her withdrew from sight. They turned off their torches and killed their radios. Tova sat alone and watched the evening progress, the line of vegetation blacken into shadow on shadow. There was a glow in the distance, some town, she supposed, but as the minutes passed this little patch of wild land was quite dark.

  She sat alone. “Charlie,” she said. She leaned back, startled, at the crackling boom of her own staticky voice from the loudspeakers, blaring into the night and the trees. “Charlie. You must be starving and you must be freezing and Jesus, mate, you must be sick as a dog.”

  What if he did come?

  Tova heard bats and thought the word “pipistrelle” with pleasure. She knew the police and the doctors were close but she felt alone, without fear. Wind pushed the trees around. She could see nothing.

  “Charlie, come on.”

  The sky was cloudy and though there must be a moon or half-moon it was struggling to break through. Tova’s eyes were adjusting. She saw motion.

  A figure emerged from the dark landscape.

  A thin man, sketched in outline, his legs buckling with each step, treading toward her with jerky strides, swaying under something misshapen.

  Tova’s heart beat hard.

  The man started to jog up the hill. He stumbled and righted himself. He shed clots of matter from what he wore. Tova tried not to rear back in her chair as he approached.

  With loud snaps, floodlights shone on the gorse. The man froze.

  Pinioned in the beams, he twitched. Police officers walked into the edge of the light.

  “Alright, mate,” they shouted, and, “Come on now, Charlie.”

  “That’s not Charlie,” Tova shouted.

  It was the other man, Neil. He was naked and much thinner than he had been. His skin was lesioned. He hunched, then hesitated and stood up again.

  Tova stared at what he wore.

  It was nothing like a crocodile, not like any animal’s head at all. It was formless, a pile of crawling, dripping, dark dough. It smeared him. In the cold glare she could make out the ruins of scales. Rot had done away with a long section of the snout and she imagined it drooping over several days, bad reptile comedy, dropping off in a clot in the car-park of some small post office.

  Tova stood. She approached him. Neil stood still as she and behind her the officers came toward him. Tova heard one of them retching. Someone shouted, “Hazmat!”

  She could smell him. An incredible reek. She could see worms on his shoulders. She did not think they were the little tentacles but the worms of rot. She imagined she could hear the elongation and turf-like split of the fibers in the meat he wore as it stretched. The police surrounded Neil, who stood, blinking and uncertain, on the slope. Officers in yellow overalls, goggles and surgical masks, came toward him.

  “Jolly good, Neil,” one of the figures said through the mask. Tova realized it was Allen. “We’re just going to give you a hand.”

  He did not resist as they picked and scooped the flesh from his face. They dropped each handful, each fragment and moldering hunk into a specimen container. Derek wiped the ooze from Neil’s face with some antibacterial astringent.

  “There we go, mate,” he said. “There we go.”

  Neil’s features appeared. His eyes were wide and his mouth gaping. He looked like a little boy.

  “Can I … is there anything to eat?” he said.

  “There we go, mate,” Derek kept saying.

  “I’m tired and this was … I had to come in.” Neil pointed again and again at the remnants of the flesh he wore. “I wasn’t going to stay out,” he said.

  “There we go. You’ll be alright.”

  Neil was hungry and confused and ripped up from days of running through barbed wire and thorns, and he was infected and mildly feverish, but in all, Derek said, he was healthy. Surprisingly so.

  “He says he doesn’t remember anything. I believe him, honestly. Nothing except for a few bits and pieces, like sleeping in some old garage. F
or some reason that stuck with him.”

  “What about the others?” Tova said.

  “He doesn’t know.”

  “But they were like a pack.”

  “I know. When the head rotted badly enough he must have sort of wandered off.”

  “Is he going cold turkey?”

  “No. I think maybe because it moldered off him, it’s like the addiction did too.”

  The police did not ask Tova to try again.

  Two days after Neil came out of the Essex wood, Simone walked naked and bleeding from a dog bite into a local radio station. Her face was foul and wet but the cow had completely decayed off her. She told the receptionist that it was time to come home.

  Tova was impatient and hopeful when the manager of a small shop found the remains of a decaying pig’s head outside his delivery entrance. There were no filaments within but that meant nothing, those fingers of intrusion being always momentary and contingent, always vanishing without evidence or remainder between intrusions. But the meat turned out not to be decayed enough to plausibly be Charlie’s. It transpired, when a threatening letter appeared, that the grotesque delivery was an Islamophobic intimidation against the owner.

  Tova continued to hope, even when a coast guard helicopter snatched two seconds of footage of a nude man climbing the cliffs of the east coast. The camera swung too wildly and quickly to see whether he wore anything on his head, or whether he was ascending or descending.

  Neil and Simone appeared together on a talk show. Neil was tongue-tied and seemed to resent every question.

  “I suppose what everyone’s really wanting to ask,” the interviewer said, “and I mean this completely respectfully …” She paused while the audience laughed nervously. “I do! Shut up, you lot! What we’re interested in is What were you thinking?” She interrupted the renewed laughter to continue. “And I mean that literally. As Dr. Bob was pointing out earlier, it’s common in these situations … you may not even know what you were thinking. We’ve all seen the footage. So do you have any memories of that time?”

  “You know, it’s odd,” Simone started to say.