They run. The great spread of grass rolls out to greet them and they skim down it, the crackle-cold air flowing like spring water into their mouths and running their hair straight out behind them when their hoods fall back and none of them can stop to pull them up again. They’re invisible, they could stream laughing past the night watchman and tweak off his cap as they went, leave him grabbing at air and gibbering at the wild unknown that’s suddenly everywhere, and they can’t stop running.

Into the shadows and down the narrow paths enclosed by dark spiky weaves of branches, past leaning trunks wrapped with years of ivy, through smells of cold earth and wet layers of leaves. When they burst out of that tunnel it’s into the white waiting glade.

They’ve never been here before. The tops of the cypresses blaze with frozen fire like great torches. There are things moving in the shadows, things that when they manage to catch a hair-thin glimpse are shaped like deer and wolves but they could be anything, circling. High in the shining column of air above the clearing, birds whirl arc-winged, long threads of savage cries trailing behind them.

The four of them open their arms and whirl too. The breath is spun out of them and the world rocks around them and they keep going. They’re spun out of themselves, spun to silver dust flying, they’re nothing but a rising arm or a curve of cheek in and out of ragged white bars of light. They dance till they collapse.

When they open their eyes they’re in the glade they know again. Darkness, and a million stars, and silence.

The silence is too big for any of them to burst, so they don’t talk. They lie on the grass and feel their own moving breath and blood. Something white and luminous is arrowing through their bones, the cold or the moonlight maybe, they can’t tell for sure; it tingles but doesn’t hurt. They lie back and let it do its work.

Selena was right: this is nothing like the thrill of necking vodka or taking the piss out of Sister Ignatius, nothing like a snog in the Field or forging your mum’s signature for ear-piercing. This has nothing to do with what anyone else in all the world would approve or forbid. This is all their own.

After a long time they straggle back to the school, dazzled and rumple-haired, heads buzzing. Forever, they say, at the threshold of the window, with their boots in their hands and the moonlight turning in their eyes. I’ll remember this forever. Yes forever. Oh forever.