She was sure she had seen through her hands, through skin and flesh and bone, and had gripped the desk in a last-ditch attempt to anchor herself to the world. A trick of the light, surely, caused by tears blurring her vision.

So why was she so frightened to face herself now?

Kat wiped her face with trembling fingers, and she could feel them, solid matter against her skin. It gave her the courage she needed to open her eyes.

A ghost looked back. Her reflection was exactly where it should be, but it was spectral; a sunblind afterimage. Her body had faded, just a little. Haltingly, she turned her head side-to-side, and the reflection mimicked her as it should. Through herself she could see the toilet stalls behind and the crinkled cleaning notices fixed on their doors, but she retained enough substance to render their words indecipherable.

The panic caged inside her chest was a feral creature, and now it threw its body against the bars. Whenever it tried to claw its way out Kat tried to imagine her breathing as a moustachioed tamer jabbing at it with a kitchen chair. Now the beast caught it in its jaws and splintered the wood into matchsticks.

Irrationally, she spun around, expecting to find her body splayed on the tiles. She had died and become a wayward spirit. It was the only rational – ha! – explanation. But there was nothing there.

‘That was Backwash season one, episode five,’ she told herself, trying to keep calm. ‘“Zenon’s Temporary Demise”.’

A sob split her open. Despair and horror poured out in a scream, long and dreadful, resounding around the toilet walls.

It only stopped when a boy pushed through the door.

Wesley tried to stay in his seat. If something was wrong, if she was upset, he wasn’t supposed to care. Everybody else in the room had seen it too. Let them play the white knight.

Except they continued with their work, Buttercliff his game, the session continuing as if it had all been the most natural thing in the world. They had seen the picture. They had looked right at her as she turned transparent, like a chameleon excusing itself from a threat. The period would be over in minutes, but he couldn’t wait. He needed to debunk what his eyes had told him – that was the only reason he was going. It wasn’t because he cared. He swore under his breath and hurried out.

Wesley followed the corridor, peering into classrooms, sure she would have looked for somewhere to hide. Every vacant room on the floor was dark and empty. It was only when he reached the stairs that he heard the scream from the girls’ toilet. He rushed to the door, hesitating to cross the boundary. The agonising cry, its seemingly endless keening, pulled him inside.

‘Is everything o—?’

He cut himself off mid-sentence.

Nobody was there.

At the sight of him, Kat tried to tear herself into three: one to gather up her laptop and bag, one to stand straight, wipe the snot from her face and smile as if everything was okay, and one to hide, hide, hide.

She held her breath as the boy stared in bafflement. Kat searched her mind for an excuse, a reasonable answer to his unfinished question.

‘I don’t know what’s happened,’ she said, the only truth she knew.

The boy didn’t answer, instead peering around the room as if there might be somebody else hiding there.

The parts of Kat’s mind scattered by panic began to draw back together. She knew this boy – Wesley, from her year. They had met before, seen each other around school. He must have seen the photo along with everybody else.