He climbed out into the afternoon, phone buzzing away silently in his pocket, vibrating against his ribs like an angry wasp. ‘Come on: you can give me the short version on the way.’

The dove-grey sky matched the granite buildings, the breeze tumbleweeding an empty crisp packet and a carrier-bag across the grass. Definitely getting colder. Logan followed the path behind the Old Brewery, taking a shortcut under the concrete Tetris block of the Taylor Building.

Chalmers dug her hands into her pockets. ‘First half of the book isn’t a diary. It’s more like some sort of slavish recreation of—’

‘The Fingermen’s dittay books. It’s a prop from the film, she stole it.’

‘Oh. . . You knew.’ A little sag, then Chalmers brought her chin up again. ‘The second half isn’t her handwriting – doesn’t match the slash-fiction we found. It’s still her, but it’s like she’s trying to make her writing look like whoever did the first part.’

Across a car park wedged in between the buildings, the yellow hatching of a box junction flaking away and scarred with potholes.

‘There’s loads of angst-ridden poetry, a bit of moaning about how no one understands her, how she hates the way the medication makes her feel, quite a lot about how she loves Anthony Chung more than oxygen. . . Blah, blah, blah. Standard teenager stuff.’

‘She’s eighteen.’

‘There’s nothing in the book about her planning to run away, or where she’d go if she did.’

They marched past Coopers Court, warm for a moment in a beam of sunlight, the concrete lump of a building acting as a windbreak.

‘What about the mysterious Stacey. . .? ’

‘Gourdon, Guv. Stacey Gourdon. Still no sign.’

Not good news: if Agnes was prepared to necklace some random tramp, she wasn’t exactly going to bake cookies for the woman screwing her boyfriend. And it wouldn’t be Anthony’s fault, would it? No, it’d all be Stacey Gourdon’s.

Be lucky if they found her in one piece, never mind alive.

‘Get on to the hospitals. See if Ms Gourdon is lying in A&E somewhere.’ Logan stepped to one side, allowing a young woman on a skateboard to trundle past, blonde hair down to the small of her back, ragged saggy jeans low enough to show off a pair of red pants and a ‘DADDY’S LITTLE GIRL’ tramp stamp. ‘If you were eighteen, running away from home, what would you take with you? ’

Chalmers’s brow wrinkled. ‘Toilet bag, makeup, hairdryer, Mr Trousermonkey, favourite clothes. . .’

‘What about your diary? ’

‘No way I’d leave that behind. My mum was like the Spanish Inquisition on a bad day, nothing was safe.’

‘Exactly. And we know Agnes’s mother’s. . . Hold on, “Mr Trousermonkey”? ’

‘Mum made him from a pair of dad’s old trousers, when I was wee. He’s tartan.’