Seeing the love of your life for the first time since she left you is one thing. Seeing her perform naked at a live art event, defecating into a condom and then masturbating with it is another thing, a thing that does damage, and a thing that Dean knew was going to be the undoing of Johnny Penguin.

Johnny was tall, beautiful with his flowing hair and bold suits, well spoken and confident, but for all his wit and spirit he had no defence against the colourless brutality of life. The world, dark and unrestrained, could pour itself into him and batter him and drown him any day of the week, and Dean had to fish him out and dry him off and teach him how to live again. Johnny was no saint, of course. He was often cruel in his descriptions (‘She looks sweaty and unfinished, like a pickled foetus’) but at the same time he was intensely vulnerable. Like Oscar Wilde missing a chromosome.

Jasmine, the love of Johnny’s life, had been on Art Foundation in Camberwell when they met. Four years later she dumped him by post from a trip to Japan and he never heard from her again. Dean saw him through the worst of it by shopping for three-piece suits, taking him to a friend’s house in the middle of the English Nowhere, and learning to make a cocktail called Death on the Back of my Hand. Someone said Jasmine had opened a cupcake shop in Cornwall. Someone else heard she was in New York with a punk rocker turned animal activist turned painter turned sex guru. Perhaps both stories were true or perhaps just one or perhaps neither, but here she was now, in East London, billed as an up and coming performance artist and writhing on a concrete floor with a dildo made of her own shit.

Earlier that night they had been doing some excellent drinking when they saw Whistler outside Bar Italia, smoking and ignoring a girl in a fur cape. She was pale and talked relentlessly, as though she might explode the second she stopped. Whistler, legendary party host, dandy, gentleman of the night, looked golden age Hollywood in a double-breasted suit and Chinese tie, pencil moustache freshly trimmed, ready for more.

‘I’m on the list for a secret art show,’ he said. ‘Sounds fishy, yes, but there’s free wine and we can go to mine after.’

They shared a taxi whose driver they seemed to terrify and twenty-five minutes later negotiated entry to a dark warehouse near Dalston Junction. The boy at the door was gaunt and angry and when Dean refused to let him put a stamp on his wrist the boy called him a ponce and stamped it on his cuff instead.

Someone had set up a bar at the centre of the concrete emptiness and the lighting was clever and the music unbearable. It was a monotone scraping noise, apparently generated by a topless fat man who sat like an abandoned hatchling in a nest of flashing electronics.

Whistler and the talking girl went to get wine. Johnny gave Dean a vexed look and Dean held his walking stick like a sword, pretending to fear attack from the other visitors. People who looked like variations of Patti Smith and Andy Warhol drifted by in streaks, silently, huddled in cocoons of hostility. They formed a crowd under a lighting rig in a far corner and Johnny cocked his head for Dean to come look. Johnny, sleek in his yellow houndstooth, fast and stunning, strode forth and through the crowd before it closed up. Dean tried to follow, but a very tall person of indeterminable gender glowered at him, deliberately lingering to disapprove of his hat and walking stick, and Dean stayed where he was.

He saw enough of Jasmine to recognise her. Mop of dark curls over pale skin, fat glasses, full lips with her trademark lipstick, outlandish, emerald green. Beyond the congealing audience she squatted and squinted and concentrated on, as it turned out, the act of shitting into a condom. Her expression was business-like. A loudspeaker was mounted to the scaffolding above her and the scraping noise was especially loud now and acquired an abrasive sharpness. Dean had the impulse to run away. When a sweet, sturdy odour asserted itself he recalled Johnny’s complaining about Jasmine’s vegetarianism. He felt something on his shoulder. As he turned, Whistler talked into his ear.

‘There’s no booze,’ he said. ‘They stuck a bar right in the middle of this horrible place and there’s no booze. Can you believe it? There’s nothing in the middle, Dean. We must leave at once.’

The talking girl tugged at Whistler’s suit. She had something urgent to say.

‘It’s Jasmine,’ Dean said.

‘I know,’ said Whistler. ‘I’m going outside for a smoke.’

Johnny looked green under the crazy light. His posture was at once upright and alarmingly limp, as though someone had run him through with a spear and only the spear was holding him up.

Dean was angry and impatient. Seeing Johnny exposed made his stomach turn. He thrust out across the crowd with his walking stick and tapped a man just behind Johnny on the shoulder.

‘What’s she doing?’ he asked the man.

The man’s facial tattoo gave him a permanent scowl. ‘She’s defiling herself with the rancid fruit of her own imperfect body,’ he said. His voice was crisp and metallic. ‘I’m her mentor. Who the fuck are you? You look like Salvador Dalí.’

‘I’m Dean.’

‘I’m Croak. You look offended. Does this offend you?’

Dean looked at Johnny. Something was happening. He was swaying. His eyes were half closed and his chin quivered. The scraping noise grew louder and louder and the lighting erratic. Dean shouted over the mounting chaos.

‘I’m worried about my friend. I don’t think he’s well.’

The man named Croak turned to where Dean had indicated and just then Johnny’s entire body began to shake as though electrified. His mouth fell open. Dean thought he might be screaming or screaming silently or crying. Croak pushed people out of the way and gestured for Dean to come through, and Dean reached Johnny just in time to catch him.

‘Help me carry him out,’ he said to Croak.

Croak motioned into the crowd and seconds later the tall person of indeterminable gender was helping them carry Johnny to the door.

‘Your friend couldn’t take it, huh.’

The gender person addressed Dean in a voice similar to the scraping noise. ‘The reality of female sexuality frightens the bourgeoisie, you know.’

Dean had an idea the gender person might be a woman. She sounded kinder than she looked.

‘And the anus,’ she said, ‘is the grave of human dignity.’

It was cool outside and there was a drizzle and in the distance there were sirens. Croak gave the gender person a conspiratorial smirk and the two of them put Johnny down on the pavement and walked back inside. They looked hot and spent and happy and full of life. Johnny’s eyes were opening.

‘What’s going on, man?’ Dean said.

‘I have no idea,’ Johnny said, entrusting to Dean his full weight.

‘D’you know,’ he said finally, ‘I think I’m just really bored.’

Dean understood now that for the last two minutes or so Johnny had been wrenching open his mouth in a single, big yawn. Whistler came to steady them both and offered Johnny a cigarette with the filter snapped off and Johnny smiled at it as one smiles at a child. Then he shrugged pleasantly and craned his neck like a howling wolf. Whistler gave him a light and it was then, as the flame dashed out towards Johnny’s face, that Dean had the sensation that Johnny was entirely transparent, that the brickwork and shimmering pavement shone through him, each ground-out cigarette and blackened chewing gum visible beneath the intricate geometry of his suit. It lasted no longer than a split second, but the sensation was so vivid that Dean thought Whistler must have seen it, too.

The talking girl was upon them again.

‘What’s with him?’ she said. ‘I thought there wasn’t any booze.’

‘Would you please shut up for one second,’ said Whistler and took out a cigarette for himself. The girl looked offended.