Hepton stared into Vincent’s room. Where the hell could they be? Wait, though: a building like this would need a fire escape, wouldn’t it? He walked back along the corridor and continued past the staircase. Just around the next corner was a door marked EMERGENCY STAIRS. He smiled and pushed it open.

He was standing at the top of an enclosed stairwell, its steps winding and made of concrete. There was a window looking out onto the hospital’s rear car park. He glanced at the dozen or so cars and saw the black Sierra parked there. He smiled again. Then he heard a sound from below him. Heels scuffing on stairs.

‘Harry?’ he called. He started to descend, then stopped. There was no sound now from below. ‘Harry?’ he repeated. He listened and heard the sound again. Footsteps, not descending now but climbing. Coming towards him. He was about to approach them, but something about the sound stopped him, something distinctly ominous. The steps were slow and even, and he could hear only one pair of feet. No Paul, then. Only a woman’s heels. Silently he retreated a few steps until he was back beside the door and staring down the twelve or so steps to where the staircase turned a corner. There was a shadow on the wall below him. Then a figure appeared on the lower landing.

Harry.

And she was holding a gun.

Her face was devoid of emotion as she saw him and angled the gun up towards his head. Hepton dived towards the door and yanked it open. He threw himself through it and into the corridor, looking to left and right. He heard Harry’s feet quickening on the stairs behind him and ran back along the corridor. The receptionist was standing at the top of the main staircase.

‘There you are,’ she said. ‘I’ve looked, but there’s no sign—’

‘Get back downstairs!’ yelled Hepton, startling her. Then he was past her, running towards Paul Vincent’s room. He realised that he should have pushed past her and down the stairs, well away from Harry and her gun. But there were people downstairs, lots of them. He couldn’t endanger all those lives. Very noble, Martin, he thought. But now what could he do? He stared at the door marked Stores. Beneath this sign was a smaller one indicating that a fire extinguisher was located within. Well, any weapon was better than none.

He saw as he approached that the door was ever so slightly ajar. Behind him, he could hear the receptionist. She hadn’t gone downstairs; instead, she had followed him along the corridor. Any second now, Harry would round the corner and be upon them. Hepton pulled open the cupboard door.