One of them could have done something.

If the text was true, then today had turned into something different. Not just about finding the card girl, not any more.

We waited. Down on the playing field, the rhythm of the hockey sticks had turned ragged: the girls had spotted us, they were missing easy shots craning over their shoulders trying to pick us out of the shadows. Little feisty birds clicking and wing-flipping in and out of the trees above us. Sun fading and blooming as thin clouds shifted. Nothing.

I said, ‘Ring it?’

‘Ring it.’

It rang out. The voicemail greeting was the default one, droid woman telling me to leave a message. I hung up.

I said, ‘It’s one of our eight.’

‘Oh, yeah. Anything else is way too much coincidence. And it’s not your Holly. She brought you the card, she’d bring you the key.’

Conway pulled out her phone again. Rang one number after another: Hello, this is Detective Conway, just confirming that we still have the correct phone number for you, in case we need to get in touch . . . All the voices were recorded – ‘School hours,’ Conway said, tapping; ‘phones have to be switched off in class’ – but all of them were the right ones. None of our girls had changed her number.

Conway said, ‘You got a pal at any of the mobile networks?’

‘Not yet.’ Neither did she, or she wouldn’t have asked. You stockpile useful pals, build yourself a nice fat list, over time. I felt it like a thump: us, two rookies, in the middle of this.

‘Sophie does.’ Conway was dialling again. ‘She’ll get us the full records on that number. By the end of the day, guaranteed.’

I said, ‘It’ll be unregistered.’

‘Yeah, it will. But I want to know who else it’s been texting. If Chris was meeting someone, he arranged it somehow. We never found out how.’ She slid down off the wall, phone to her ear. ‘Meanwhile, let’s go see if Little Miss Text’s fucking us around.’

McKenna came out of her office all ready to wave us goodbye, wasn’t a happy camper when she found out we weren’t goodbyeing anywhere. By now we were front-page headlines all round the school. Any minute the day girls would be heading home to tell their parents the cops were back, and McKenna’s phone would start ringing. She’d been banking on being able to say this little unpleasantness was over and done with: just a few follow-up questions, Mr and Mrs, don’t worry your pretty heads, all gone now. She didn’t ask how long it would be. We pretended not to hear her wanting to know.