She keeps her voice level, but I don’t think I’m imagining the bitterness in it. I’d much rather be with Thistle than with the blonde, or with anyone. But I can’t tell her that.

‘She didn’t look like a teacher,’ I say instead. ‘Or a student, or a cleaner, or a parent. You think this place gets many visitors from outsiders?’

‘You think a teacher can’t look that good?’

‘I think a teacher that age can’t afford those clothes.’

We’ve reached a door with a sign on it. SHANNON LUXFORD.

‘Is it normal for a teaching assistant to have his own office?’ I ask Thistle.

She shrugs, and knocks on the door.

I didn’t expect him to be in—most people don’t close the door if they are—but he is. The lock clicks, and Shannon Luxford appears.

Up close, he looks less like a superhero. His eyes aren’t quite symmetrical, and he has a pimple under one ear. But he’s taken care with his appearance. His hair is curled perfectly at the front, and it’s short enough at the back to indicate that he’s had a haircut within the last two weeks. He smells of expensive aftershave and fabric softener. I’d guess his age at twenty-two or twenty-three.

‘Can I help you?’ His eyes flick from me to Thistle, and a smile spreads across his face. His gaze lingers on her breasts. ‘Agent … Thistle, right? Nice to see you again.’

‘This is my associate, Timothy Blake,’ Thistle says. ‘We just had some routine follow-up questions. Do you have a minute?’

‘Sure.’ Luxford opens his office door wider and steps back. ‘Mi casa es su casa.’

There’s a new stiffness in his neck, and the tendons are standing out in his wrists. This could mean that he’s nervous. Maybe he’s expecting bad news about his boss. Or maybe he’s always nervous around cops, like I am.

‘Can I get you anything?’ he asks. ‘Coffee? Tea? Water?’

‘No thanks,’ Thistle says. ‘We—’

‘I’ll take a coffee,’ I say.

Thistle grits her teeth.

‘Uh, sure,’ Luxford says. ‘Cream? Sugar?’

‘Both, please,’ I say. ‘And salt.’

He blinks. ‘Salt?’

‘Just a pinch,’ I say.

He nods. ‘Reduces the bitterness, right? They drink it that way in Japan. I go skiing there every winter.’

I prefer salted coffee because it tastes like blood. I doubt that people drink it in Japan. But he came up with the story almost instantly. Either he’s a practised liar, or someone in Japan has played an excellent prank on him.

He calls out the door, ‘Liz, can you grab a Japanese coffee for my guest? Sugar, cream and salt. You heard me.’

He closes the door without waiting for a response. I assume teaching assistants don’t have secretaries—he might be in the habit of using students like servants.