Elated, Hepton darted back into the flat, stubbed out the flaming newspaper in the sink and poured some water on it. He went back to the video screen at the front door and saw that people were already emerging from their apartments, milling in the main hallway downstairs. He went out onto the veranda and waited. There was a stiff breeze and he breathed hard, staying calm. The Thames was smelling like a sick old pet, but he didn’t mind that. He leaned out over the balcony and peered down onto the veranda of the flat beneath, then pulled himself back. There was no need to be rash. He could take the stairs to ground level, the same as the other inhabitants. He already had the evidence of his own eyes and his continuing life to the fact that Harry did not like a crowd. She enjoyed doing her slaying in private.

Suddenly he heard what he had been waiting for: approaching sirens. He rushed back inside and out into the corridor. A couple of people, looking as though they had been disturbed in the act of coitus, were standing by the lift, their clothes disarranged. The man was frantically pressing at the button beside the doors.

‘I shouldn’t think you’ll get much joy,’ Hepton informed him. ‘These things shut off when there’s an alarm. It’s much safer to use the stairs.’

‘Is there a fire?’ the man asked.

‘Yes, upstairs,’ said Hepton. ‘We’d better hurry.’

The three of them set off downstairs together. At the third landing, they joined a slightly larger group.

‘Is there a fire?’ someone asked.

‘Yes,’ the man with Hepton said, mimicking him. ‘It’s upstairs.’

Between the third and second landings, Hepton, to the rear of the small party, saw that someone was pushing their way back up through the descending group. There was always someone, someone who’d forgotten a treasured memento or the pet cat. He was about to remonstrate when he realised it was Harry. She was pushing hard now, her anger showing. And in her eyes he saw a kind of madness. There could be no doubting: she was out to kill him, witnesses or no.

Then she glanced upwards and, separated from him by only a handful of bodies now, saw Hepton. Her eyebrows rose in victory, and she dug a hand into the pocket of the checked jacket she was wearing. But the hand stuck there as somebody tried to squeeze past her downstairs.

‘You should go back, love,’ someone warned her. ‘Save yourself. Never mind what’s up there.’