There would be a simple explanation, she told herself. But Lennie had never done this before – she was reliable, she’d never gone off on her own. But then, she’d never been uprooted before, had she, never been pulled out of a school where she’d been happy and had a ton of friends, separated from a man who’d wanted to be her father, dragged off to a city she’d only ever visited in order to share a room with her mother and have someone she’d loved be violently killed.

Lennie, I’m sorry – I’m so sorry.

And what if the explanation wasn’t simple? What if she hadn’t just gone off?

Feeling sick, she faced it: if Lennie had been taken, it would be her fault. Her work, either Hinton and Farrell or Becca, would have made her a target. Because even if Becca had been abducted at random – a pretty girl coming home in a unlicensed cab in the small hours, alone, tired, possibly drunk – the likelihood of the same applying to Lennie – taken in broad daylight, in the two hundred yards between the school gates and the door of her grandmother’s car – was nil.

And then there was the other possibility. With another nauseous swell, she thought of that night. If Corinna had been killed for that …

The car in front baulked at an amber light, forcing her to stamp on the brake just as the phone rang through the Bluetooth.

St Saviour’s.

‘Mrs Lyons? It’s Pam Travis at the school.’ She was breathing as if she’d just finished a spin class. She wasn’t radically unfit, Robin realized suddenly, she was asthmatic. Years ago, a bloke she’d arrested had had an asthma attack on the way to the nick. Even after they’d got him an inhaler, his breathing had sounded just like this: laboured, hard work. God, why was she such a bitch?

‘I went down to the gym for you, to chess club.’ She paused, took a painful-sounding breath.

‘Thank you so much.’

‘No problem. Elena wasn’t there.’ Wheeze. ‘But on the way back, I bumped into Mrs Shah, who teaches Chemistry.’ Wheeze. ‘She was supposed to have had her this afternoon, she said – Elena’s class had double chemistry at the end of the day – but she wasn’t there.’ A cough. ‘So I checked the register for the lesson before that, French, and she wasn’t there, either. We think she left school at lunchtime.’

By the time she made the turn into Corinna’s road, Robin’s nerves were jumping. Lennie wasn’t at Dunnington Road – Christine had called when she reached home. She’d even checked Dennis’s tiny shed.