Edwards’s eyes are wide. I get the feeling he honestly didn’t know about the blood. This isn’t what he was worried we would find.

Thistle’s playing bad cop, so I play good. ‘You seem like a nice guy,’ I say. ‘I’m sure you didn’t expect anyone to get hurt. If you just tell us what happened, we’ll be able to—’

‘Nothing happened. I don’t know how that got there.’

I open the least dusty archive box and start digging through the contents. Just employment records, like Edwards said, plus some receipts and bills for utilities. None of them less than three months old. No references to Biggs, Ruthven or Luxford. All the surnames in here sound like occupations—Tailor, Smith, Cook, Mason, Post. I’m checking phone numbers and addresses as I go, and so far nothing matches either victim. Got to work quickly. Soon Edwards will wake up and realise we need a warrant for this.

‘I want to call my lawyer,’ Edwards says, like he’s reading my mind.

‘Go ahead,’ Thistle says. ‘But you know you’re not under arrest?’

Edwards clenches his jaw and says nothing. He pulls a phone from his pocket, checks the screen and walks out of the container.

Thistle checks her phone, too. ‘No service in here,’ she says. ‘What are you thinking, Blake?’

‘Not sure yet.’ I close the archive box and go back to the wall planner, chewing my lip.

‘I’ve never seen a spatter pattern like that,’ Thistle says, looking at the blood.

‘It’s not exactly spatter. There are prints in it.’

‘How fresh do you think it is?’

‘Day before yesterday, I figure. No older.’

‘Okay. You be the victim, I’ll be the killer.’

I turn to face Thistle. She takes a pen out of her pocket.

‘I come at you with a knife,’ she says, and slashes at me with the pen. I raise my hands instinctively, and the nib swipes across my palm.

‘So you’re hurt,’ she says. ‘Your hand is bleeding. Do you trail it across the wall planner as I push you backwards?’

She steps forwards, and I step back, like we’re dance partners. I leave my arm outstretched, keeping my fingers an inch away from the planner. ‘Doesn’t feel right,’ I say. ‘And it’s not a trail of blood. It’s just spots.’

‘So maybe you lean against it.’

‘Twelve times? With only finger each time?’

‘Is it the same finger?’ Thistle asks.

‘The print looks the same, yeah.’

‘Okay, forget that for now. But let’s pretend that you’re already bleeding.’

‘All right,’ I say.

‘I come at you again, and you push back.’ She comes at me with a slow-motion stab to the sternum. I put my hands on her shoulders and give her a half-hearted push back.

‘You fall,’ she says, and pushes me over. I slowly tumble to the floor.