“I’ve just left everything I’ve known for the last four years, and you’ll try not to disappoint me? Good start.” She risked another look. “Go right. Doorway on the corner.”

They ran doubled over. He made a much smaller silhouette than she did. Hers was more graceful. This time the space they had to hide in was narrow, and they had to press themselves in, body to body. Their height difference meant that Petrovitch didn’t know quite where to look. Rather than staring at her armored chest, he looked up into her big brown eyes.

“I mean it,” she said. “If you let me down, I’ll kill you.”

“I kind of assumed that.”

“Good: just so we both know where we stand.”

There were footsteps, the sound of broken glass underneath booted feet, voices. Petrovitch and the sister froze and waited. She turned her head to hide her face, and Petrovitch could see the stubble on the side of her partially shaved head.

Someone laughed, kicked a loose plastic bottle across the street, then shot it for target practice. Their effort was greeted with a chorus of jeering, and a fusillade of firing.

When it had finished, they moved on.

“Rabble,” she muttered. “Take away their guns and they’re nothing.”

“It’s not what Father John thought. It’s not what you thought.”

“Forgive me for feeling uncharitable. That stink on the wind is my church.” She checked the road they were going to take was free of militia. “Keep to the right-hand side. There’s a red glass-fronted building at the end of this street. Turn right and go into the car park behind. We can cut through.”

She eased herself out and ran again, darting between cars, leaping over the urban debris of decay. If Petrovitch hadn’t known where to look, it would have been impossible to follow her. She was like a gray ghost, disapparating at will.

He set off after her in his own clumsy fashion, catching a few moments rest where he could press the street furniture hard against his back before moving again.

There was a body in the middle of the road, forever frozen in a sprawled, crawling, spider-like pose. Shot in the back, then shot again. He belatedly looked around him, trying to think like Madeleine did, weighing up cover and spying out shadows.

It wasn’t the same as running from a few overweight St. Petersburg cops.

He kept going, even though he’d lost sight of her. It was a confession of faith that she was ahead of him, and she’d be where she said she would be when he got there. And he’d get there, or die trying.