Nathan began to doubt himself, even as he worked. It had been the merest, most fleeting glimpse: only part of her face had been visible. She had been wrapped up in layers of clothing, a rag pulled tight around her neck to ward off the plummeting temperatures; because, ever since the Shoal had abandoned them, the temperature had dropped even as the light failed. It didn’t take a genius to realize the coreship was dying.

Nathan pulled himself up inside the second air-ambulance, along with Kellogg and the other new volunteer whose name he’d already forgotten. The ambulance’s jets began to whine, preparing for takeoff, but his mind was on other things.

He was almost certainly mistaken, of course, as he imagined he saw Ilsa everywhere he looked: in the faces of the troopers and volunteer aid workers, or among the refugees who vastly out-numbered them all; or the corpses that had come to fill the streets and canals as the fighting intensified.

But then again, this might have been her. It might have been Ilsa. If he could find her . . . if she was still alive . . .

Nathan hopped back down from the open rear of the ambulance. He could see no sign of the refugees, but he guessed they were heading for the shores of the canal. His fluorescent plastic waistcoat – meant to identify him clearly as a non-combatant – flapped around his waist in the backwash from the jets.

‘Nathan!’ Kellogg bellowed down at him. ‘What the fuck do you think you’re doing?’

Nathan looked up, shook his head. ‘I saw someone I know,’ he yelled over the noise.

More than likely the refugees intended to wade across the canal under cover of darkness, since the bridges were frequently targeted. If they could get to the other side, they had a chance at escaping the worst of the fighting.

‘Nathan, get the fuck back in!’ Kellogg yelled again. ‘Once this thing goes, it goes!’

‘I’ll find my own way back,’ Nathan replied, and started to jog away, heading towards the canal. Kellogg yelled something else, but the words were lost as the ambulance’s VTOL jets lifted it high above the ground. It tipped its nose in the direction of Third Canal and northwest, and began to accelerate.

The streetlights had been down ever since Peralta had targeted the city’s primary fusion reactor systems. Nathan stripped off his waistcoat and shoved it deep inside a pile of rubble.

He jogged on past the ruined mall and kept going, squinting into the deep shadows as he went. He alternated between running and walking until he finally arrived exhausted at the banks of First Canal several minutes later. His bones ached, and more than ever he felt the slow onslaught of late middle age.