Amber was sitting on top of a nearby dryer. Her feet were crossed and she was swinging them lightly so that her shiny black shoes bumped softly against the side of the machine. She was looking down at Bailey with an expression of detached interest.

‘Awake? Good. For a horrible moment I thought I’d put you in a coma or something. But I guess I did pay enough attention on that control and restraint course after all.’

‘Why didn’t you kill me?’ croaked Bailey.

‘That would have defeated the point. At least one of you has to be alive. For him. He likes them to be alive… for a little bit at least.’

‘Why didn’t you didn’t scalp her?’ Bailey nodded over at Poppy’s corpse.

Amber screwed up her face.

‘Yuck! I don’t do that! What a thought! The scalping… that’s Leonard’s thing. No… I just plain old killed her because she was in the way. And her hair isn’t as nice as yours. Leonard’s never been into undercuts,’ she said, referring to Poppy’s hairstyle. ‘Yours is much more up his street.’

‘You choose them for him?’ Amber’s depravity nauseated her.

‘Sometimes,’ she shrugged. ‘And sometimes he just likes a bit of pot luck.’

‘Where is he?’

Amber looked at her watch. ‘Oh, he’ll be here soon enough. He’s usually pretty punctual.’

‘I thought it was tomorrow that he was due to come in.’

‘It is tomorrow, silly. It’s gone three o’clock.’

At the mention of timings, a niggling unanswered question re-emerged in Bailey’s mind.

‘Why does he kill on a sixteen-day cycle?’

Amber frowned as if the answer was obvious. ‘Well, that’s the way the rota works here. Every sixteen days I’m scheduled to be down here in the basement. Getting him in and out and around the prison requires a certain amount of facilitation shall we say, so it helps if I’m here to welcome him in.’

The rota. Bailey wanted to kick herself for not noticing it earlier. She hadn’t spotted the connection between the dates on the rota and the scheduled locations of the prison officers because she’d been too busy looking at the locations of the murders themselves, only one of which – Alice’s – had actually occurred in the basement.

They lapsed into silence. Bailey took the opportunity to study Amber more closely, marvelling once again at her chameleonic transformation from Felicia Lee into Amber White.

‘How did you manage to get a job here?’ asked Bailey.

‘Fake references and “good interpersonal skills”. It’s a lot easier than you think.’

‘You’d have made a good undercover police officer,’ Bailey admitted.

‘People see what they want to see. They take stuff at face value. If they’re expecting to see a prison officer, that’s what they’ll see.’

‘Sharon recognised you though, didn’t she? That fight in the canteen. You got your glasses knocked off and that’s when she recognised you. She knew you better than most because you were cellmates. She was trying to blackmail you, wasn’t she?’