He made a low growling sound in the back of his throat, but he could see I wasn’t going to give in. As soon as he was in the car I tore off, yanking the steering wheel and taking the corner a bit too fast, the wheels skidding on the snow that was still lying on the road. For a heart-stopping moment I thought I was going to flip the car into a hedge, but I managed to control the skid and keep going.

Liz’s house wasn’t far from the school, and when we arrived I’d barely stopped the car before Leon leapt out.

That’s her car, he told us, nodding at the sleek black sports car I’d been seeing everywhere, parked outside the main entrance. It was Liz who’d been following me, not Mike. I’d been so blinded by my past relationship with him that I hadn’t stopped to think it might be something to do with the case.

‘Paige, you and Leon stay here. I’m going to check her office first.’

I nodded, unwilling to do as Singh asked, but knowing I had to keep Leon safe. As he walked away, he glanced back over his shoulder at me, then went into the main building.

She won’t be in her office, Leon told me, looking past the building towards the residence. She’ll be in there.

I gritted my teeth. We need to stay here and wait for more police. It’s not safe.

Why the hell did you bring me here, then? he asked, frustration making him animated when he signed. We need to stop her!

He was right, and it didn’t take him long to convince me.

Fine. I’m going to check the residence, I told him. But you need to stay here.

No, I want to come with you, Leon insisted.

Absolutely not, I replied with a glare. You told me Cassie’s in danger. I’m not putting you in danger too. Stay here, and if DS Singh comes out again, show him where I’ve gone.

He shot a furious look at me, but stood back against my car with his arms folded. Casting a glance at the main entrance, in case Singh was on his way back, I set off round the corner.

As I approached the residence my heart sank when I realised I wouldn’t be able to get in. The door was locked, and I could hardly ring the bell and let Liz know I was there – if she really was inside.

Casting round for something I could use to break in, I hit on a plan. I balled up some snow and flung it at an upstairs window, hoping one of the boys was up there. The first and second snowballs brought no joy, but after the third one thumped against a pane of glass a small face appeared at the window. It was Kian.