The school is a rambling collection of redbrick buildings that rears up on the east of the village, behind a complicated road junction of traffic lights and underground tunnels. The River Bat, which starts in the mountains behind our house, has grown wide here, and it rushes past, caught behind the concrete wall that leads to a squat bridge.

It took me a while to cross the road – I didn’t know which way to go, and the pedestrian tunnel was dark and damp. It’s a relief to be out of it now and in the right place, staring up at the sprawling jagged skyline and the huge old brass bell that swings in the tower over the main school building. I shiver as the sun disappears behind it.

BROADMERE ACADEMY reads the shining green sign on the metal gate. There are points on the ends of all the letters, like spearheads. I smooth down my good dress – a faded dusky-blue one that Nan made for me to grow into – and retie my boots. It’s suddenly quiet, all the noise of the town behind me, and I have no idea what I’m about to get myself into. From out here, I can’t see anybody. No students on the steps; no movement in the windows. Nobody loitering out here like me.

I take a big breath, push open the gate, and head up the steps.

The wide glass doors open automatically as I loiter outside them, looking at my own reflection. My heart is tripping; my fingertips numb. I take a breath and step into a small lobby. There’s a silver box on the wall and a button that says PRESS FOR ATTENTION, so I swallow hard and press it.

There’s a long silence. I stare at the silver box, wondering whether to press the button again, and then there’s a buzzing noise and a woman’s voice breaks out, making me jump.

‘Yes?’ it demands.

‘Uh, my name is Stella Brigg. I called yesterday . . .’

‘Come in,’ says the voice.

There’s another buzz, and the door opens out into a bright reception area with a ridged navy carpet and a long, pale wooden counter. A tiny woman with short curly hair and a sharp chin sits behind it on a stool, peering at me.

‘So you’re our trial student,’ she says with a thin smile. ‘Welcome to Broadmere. I am Mrs Edge.’

‘Hi.’ I manage a smile, sidling up to the counter. On the ledge behind it is a computer, a phone, a tray of papers and a huge silver spike.

‘What papers do you have?’ Mrs Edge asks.

‘Uh, none. Sorry . . .’

‘Ah, one of those,’ she says, tilting her head with a small frown. ‘And you’re all alone in the world? No parents?’

‘They, um . . . They died when I was small. But I do have my nan.’ I don’t mention that she’s a ghost. ‘She’s . . . housebound.’