Becca starts to answer, but she gets hit by a flood of giggles. She falls backwards on her bed, arms spread, and lets the laughter jiggle her whole body like popcorn popping inside her.

‘Nice to see you quit bitching,’ Julia says. ‘So are you going to the dance?’

‘Course I am,’ Becca says. ‘You want me to go in my swimsuit? ’Cause I’ll do it.’

‘Lights out!’ one of the prefects yells, slamming her hand against the door. They all turn the light off at once.

They practise in the glade. Selena brings her little battery-powered reading light, Holly has a torch, Julia brings a lighter. The night is thick with clouds and cold; they have to grope their way down the paths to the grove, wincing each time a branch twangs or a clump of leaves crunches. Even when they come out into the clearing they’re nothing but outlines, distorted and unreadable. They sit cross-legged in a circle on the grass and pass the lights around.

It works. Uncertainly at first: just small tentative flickers, half a second long, vanishing when they startle. As they get better the flickers strengthen and leap, snatching their faces out of the dark like gold masks – a little wondering sound, between a laugh and a gasp, from someone – and then dropping them again. Gradually they stop being flickers at all; rays of light arrow up into the high cypresses, circle and flitter among the branches like fireflies. Becca would swear she sees their trails scribbled across the clouds.

‘And to celebrate . . .’ Julia says, and pulls a pack of smokes out of her coat pocket – it’s been years since anyone asked Julia if she’s sixteen. ‘Who was saying this wouldn’t come in useful?’ She holds up the lighter between thumb and finger, brings up a tall stream of flame, and leans in sideways to light a cigarette without singeing her eyebrows.

They get comfortable and smoke, more or less. Selena’s left her reading light on; it sets a vivid circle of bowed winter grass soaring in mid-darkness, bounces off to catch folds of jeans and slivers of faces. Holly finishes her smoke and lies on her stomach with an unlit one in the palm of her hand, focusing hard.

‘What’re you doing?’ Becca asks, scooting closer to watch.

‘Trying to light it. Shh.’

‘I don’t think it works like that,’ Becca says. ‘We can’t just set random stuff on fire. Can we?’

‘Shut up or I’ll set you on fire. I’m concentrating.’

Holly hears herself and tightens, thinking she’s gone too far, but Becca rolls sideways and pokes her in the ribs with a toe. ‘Concentrate on this,’ she says.

Holly drops the cigarette and grabs her foot; Becca’s boot comes off, and Holly scrambles up and runs with it. Becca hop-gallops after her, giggling helplessly and yelping under her breath when her sock comes down on something cold.