“So why did you try and save that girl?”

“I didn’t try,” he whispered defiantly. “I succeeded.”

Father John was waiting for him at the bottom of the staircase, holding up Petrovitch’s bag in one hand. His expression said that he’d won at least one small victory.

Petrovitch took the bag from him, unzipped the pouch and slid his hand inside. The rat had gone. All he found was his nearly-spent cash card and a flimsy piece of paper.

“Oh, this has gone completely pizdets.” He pulled out the paper, knowing what was on it already. But he still had to look.

It was a Metropolitan Police Evidence Seizure form. A serial number, a few ticked boxes, and a place for the officer’s printed name and signature. Petrovitch screwed it up in his fist and threw it at the floor.

“It turns out you didn’t need to come back here after all,” said the young priest. “I appreciate the irony, even if you don’t.”

“Why the hell didn’t the bastard ment tell me this in the hospital?” Petrovitch bent down to scoop up the crumpled form, and laboriously started to flatten out the creases over his knee.

“I’m sure he had his reasons. By the way, this is a church. I’d appreciate you not swearing in it.”

Petrovitch considered his options. If the priest didn’t hold to turning the other cheek, hitting him might end badly. But just skulking off didn’t strike him as being appropriate either. “Past zakroi, podonok.”

Though the words were incomprehensible, his sentiment was resonant in his delivery. Father John’s face grew hard, and he took a step forward. “Get out.”

“Gladly.” Still pressing the piece of paper flat between his hands, he walked toward the doors. He caught sight of Sister Madeleine standing quite still beside the tower staircase.

He wondered if she would have intervened between him and the father. He knew it was her duty, but she looked so disappointed with him that he rather thought she would have just stood by and watched him get the beating he most likely deserved.

6

Petrovitch had had enough; enough for one day, most likely the week. And still he didn’t go home.

He rode the nearby Circle Line tube to South Kensington, then the underground travelator the length of Exhibition Road. All the way, he felt a dull, distant fear, a sense of having done something that might mean nothing or everything. He’d succeeded in saving a stranger—this Sonja Oshicora—and failed himself: burned out his heart, become exposed to the unwanted attentions of both criminals and police.

He’d been noticed, and that wasn’t what he wanted at all. Time would tell whether he’d been snagged enough by events for his life to unravel like an old knitted jumper.

He still had one place of safety though, somewhere he could slip into a comfortable, familiar role without anyone asking stupid questions like “why?”

Pif was there already, standing at the whiteboard, marker pen in hand, perfectly still but for the flick of her eyes. She was so absorbed in her work that she didn’t initially notice Petrovitch wander in and slump into a wheely chair behind her. The chair rolled back across the floor and clattered into a redundant filing cabinet, empty but for empties.

He leaned back and pried two strips of an ancient set of Venetian blinds apart to see the world outside. “The limits on that integral should be minus infinity to plus infinity, not one to infinity,” he said. “It’s a waveform.”

“It wasn’t meant to be,” she said, “when I wrote this stupid equation out. Where have you been?”

“Getting shot at.” He let the blinds ping back. “Being thrown into the back of an ambulance, I think, or how else would I have got to the hospital? Having my internal defib machine poked. Nearly thrown off the top of a church by a two-meter-tall nun.”

“Orly?” She stepped forward, made her black hand blacker by rubbing out the offending symbols and replacing them with the correct ones, using her impossibly neat copperplate.

“Yeah. Really.” He unzipped his jacket and peered at his chest. The ends of black thread sprouted from his skin like a half-buried spider. He had a thought and scooted across the room to his desk. Buried in the bottom of a drawer was a T-shirt, the relic of a death metal concert some six months earlier.

Pif turned around just as Petrovitch had shucked his jacket onto the back of the chair.

“Eww,” she said. “Sam, some warning, Okay?”

He ignored her protests and dragged the black T-shirt on over his head. It was slightly too small; it accentuated his thinness and rode up above his waistband when he raised his arms.

“Have you got anything to eat?” he asked, looking through the rest of his desk, then under the piles of printout and monographs. “I’m not feeling so good.”

“In a minute,” she replied, glancing back over her shoulder at the whiteboard.

“I’ll never do your coding for you again.”

“All right, all right.” She threw up her hands and raided her bag for an energy bar.

When she’d launched it across the room at him, and he’d missed it, she pulled her own chair toward his and sat backward on it, resting her chin on the backrest.

Petrovitch scrabbled on the floor for the foil-wrapped bar, and crawled awkwardly to sitting again. They looked at each other, then she reached forward and took his chin in her fine fingers, turning it left and right. Her fingernails were painted with randomly generated Mandelbrot sets.

“How bad is it?” Her beaded hair jiggled softly as she talked.

“Bad enough,” he said, and finally tore through the wrapping. He continued around mouthfuls of sweet, sticky crumbs. “The defib machine took too long to kick in, and then it wouldn’t stop firing. A lot of heart muscle had gone anoxic, and I won’t get that function back.”

“What are you going to do?”

“I have two options. Get a new heart or die soon.”

She blinked slowly. “You mean cake or death?”

“Pretty much, except the cake I want costs two hundred and fifty kiloeuros, plus expenses.”

Pif whistled air out of her mouth. “So what are you going to do? Will the university spring for it?”

“I’m a private student. The foundation that supplies my scholarship will cover it.” He screwed up the wrapper and dropped it in the bin. “Have you anything else?”

“Yes, but… that’s very generous of them. You’ve talked to them already?” She rolled away and dug out another energy bar.

“I didn’t want to hang around. I haven’t exactly got time on my side. It’ll happen next Monday, when the funds are in place.”

Pif was distracted again by her equation. She swung around to face it. “Why did you say it was a wave?”

Petrovitch held out his hand for the energy bar, and she placed it deftly without looking around. “I don’t know. You’ve written it like a zeta function, but it looks more like the bastard child of a Fourier transform.”

“I should be able to solve this.” She glanced at him as he crammed his mouth with food. “Do you want second place on the paper?”

“It can’t hurt: Ekanobi and Petrovitch, twenty twenty-five. What is it?”

“Quantum gravity. Part of it, anyway.”

He stopped chewing and got up slowly, energy bar lying forgotten on the edge of his desk. He walked to the board. “Which part?”

“The last part. I’m going to do all the calculations again, from scratch, and see if I can get to this point again. I’ve got it all written down…” She was breathless, more than that, hyperventilating. “Sam, I just caught a glimpse of creation.”

Her body started to sway, and Petrovitch caught her, and managed to get her head down between her knees.

He crouched next to her, feeling a cold sweat spring up on his own forehead. “You’ve probably made a mistake, somewhere,” he said.