With Misha gone, Harper told Will what she’d found out about Mae and Molly, like how they’d died of Spanish flu just weeks apart, and that Will’s best friend Vince had also died during that time, probably of the same thing. Harper remembered from the book she’d read that the flu had spread very quickly among soldiers near the end of the war, and to almost everyone else when the soldiers returned.

Will didn’t say a word. This wasn’t just history to him. He belonged to that time.

Quietly, she went back to a file she’d been looking through. Inside were yellowing pages, thin and lined. Lists of names on one, another headed Drills. The file name was J Cadets. Will always lit up when he talked about cadets. It was the only thing he’d liked at school.

‘This is from when you were here,’ Harper said. ‘What do you think the J is for?’

‘That’s easy. Junior.’

She found a black-and-white photograph: about twenty boys in smart clothes standing with rifles. On the back in loopy script: Riverlark Cadets, 1913.

She picked Will out before he did. He must have been twelve here, same age as Harper, holding a gun in the schoolyard. He pointed out Vince and stared for ages. The photo was so recognisably Riverlark: the old brick building with its tall windows and spire.

Harper took it closer to her, suddenly. A face in the background made the hairs on her arms stand on end. ‘Who’s that in the window?’

‘It’s you,’ Will grinned. ‘Well, it’s really Mae. She wanted to be in the cadets with Vince and me. She was always spying on our drills. Molly fancied it for a bit, too, but she gave up when it was clear there was no way. Not Mae though. Once she dressed as a boy and tried to blend in but some of the others ratted on her. Didn’t matter what punishments they gave her though, Mae kept trying to be a cadet. I remember Vince had the bright idea to give Mae and Molly our pins. Cadets were given a special one—a fish blowing bubbles, blue and shiny. Well, that was fine for Molly, she was happy to have Vince’s and she didn’t say any more about being a cadet. But when I gave mine to Mae she looked angrier than ever. Still took it though.’

Harper was staring at him with her mouth open. When he stopped telling the story she shivered hard.

‘What’s wrong?’ he said.

‘I found one. Outside the gate. Earlier this year I got a feeling that there was something wrong with it. Remember when we met I asked you if you’d hurt anyone? It was this hunch I had about the badge or the pin, whatever you want to call it. I was convinced it was haunted. Corey got injured, and then this girl called Briar. I’ve never said this out loud but I thought it was the badge doing it. I threw it in the river.’

Will jerked his head in surprise.

‘Why didn’t you tell me?’

‘I was scared. At first I thought it could be yours. And then I thought you’d be angry that I’d thrown it away. But the thing is, it seemed as if it came back. It kept showing up like it wanted to be seen. Right now it’s in my bedroom, only it seems like an ordinary thing again. My grandmother even said it was hers. That she’d found it at the river ages ago. That got me even more confused. I thought she couldn’t have. But now I have a theory.’

‘More than one badge?’ he said, and Harper nodded.

She thought of the one she’d thrown in. If only she hadn’t. It could have been the one Will gave to Mae.

‘Tell me more about Mae,’ she asked.

‘There was no one like her. She tried joining up before I did.’

‘For war? But you had to have a medical, they’d have seen she was a girl.’

‘True. Though they couldn’t tell that I was fourteen, could they? Mae had tricks up her sleeve. Get this: she snuck onto a ship full of recruits that was heading to Egypt. She was all dressed for it. Cut her hair, borrowed whatever kit she could. Turned out she had the wrong boots. That was all. She might have got away with it but once they spotted those, they chucked her off. Took her a long time to get over that.

‘When Vince and I signed up to go, Mae couldn’t hide how she felt. I can’t imagine her being a nurse, like you told me. She was the one who would take one look at our injuries from climbing trees and such and say, “It’s just a scratch, you’ll live.”’

Harper smiled. ‘That’s what my mum always says, and she’s a nurse, too.’

There was no further trace of Mae Lamb in the archives. She was just a name on the roll, and a face in a photograph she wasn’t supposed to be in.

Along the river path on her way home, Harper noticed how different Will had become. When they’d first met, he smiled at everything. He was almost too happy for a ghost. That wasn’t true any more.

‘Will, you seem sad.’

‘Do I?’ He smiled but it wasn’t very convincing.

She gave him a look.

‘All right. See, when I got here I was happy. Here was the world all over again. The sky, trees, birds, dogs, people. Even school. But seeing’s all there is for me. I can move a leaf from here to there. I can turn a light on and off. I can watch other people living.

‘And then you could see me. I like talking with you but it’s made things harder. Made me remember what life was like when I had Vince and Mae and Molly. And my sisters and my parents. And a future.

‘Every day, I feel worse. I can’t help it. I thought I’d have more freedom when I got back to Riverlark but it’s a trap.’

Will was in his own kind of lockdown.

‘I don’t know how to help,’ Harper said.

‘You can’t, and don’t take that the wrong way. I asked you for help when we met but I’m un-asking you now. I just know I’m here for a reason.’

They reached the part of the river that he’d called the swimming spot. The water was deeper and darker here. It was nearly six o’clock and the air was filled with the high notes of crickets. Will could only ever look back and remember his larking days. Kids running to this place to make the most of lunch break. Some leaping into the river without a worry. Others watching, cautious or fearful. Clothes and shoes hastily left on the grassy banks.

Harper felt guilty because even though she could see how sad he was, she liked having Will around.

‘This is your epilogue, Will,’ she said, ‘That’s the bit of a story that comes after The End.’

He nodded slowly and looked at the sky. ‘I like that.’

‘You’ve never told me about the end. I mean, what happened to you.’

‘You wouldn’t want to hear it.’

She waited for him to look at her. ‘Yes, I would.’