“So just run it past me again,” said Dionna.

“I’m him,” said Mr Carter, pointing at Ryan, who was looking increasingly weary. “And he’s me. It’s really that simple.”

“You are Ryan.”

“Yeah.”

“But you look like Mr Carter.”

“I know. That’s the big downside.”

“Ha ha,” said Ryan. “Good one. Think about what it’s like for me having to live with this stupid face.”

“Oo! That’s not very teacherly of you, Mr C,” said Mr Carter. “That’s hurt my feelings. I may have to report you to OFFHEAD.”

“OK, this is nuts,” said Dionna, getting up. “I don’t believe it.”

“Why would we lie about it?” said Ryan. “We really stand to gain nothing from this lie.”

“I have to say that me and Mr Carter are, for once, in agreement,” said Mr Carter.

Dionna shook her head. It was all very strange. She had just been passing by, looking for Ryan, when she’d heard Mr Carter – who she assumed, as she might, was Mr Carter, what with him looking and sounding like Mr Carter – say that the school was going to be shut down and seeming happy about that. She’d glanced through the window. And then Mr Carter had beckoned to her.

She’d gone in and sat down. She’d expected to be told off for eavesdropping or something. What she hadn’t been expecting was for Mr Carter to start explaining that he wasn’t Mr Carter, he was Ryan, and that Ryan was Mr Carter.

“OK. If you are Ryan—”

“No, I’m Mr Carter,” said Ryan.

“Sorry,” said Dionna, turning round. “If you’re Ryan—”

“Got it,” said Mr Carter.

“Why didn’t you tell me this earlier?” she demanded.

“Well, I didn’t think you’d believe me,” said Mr Carter.

“Why do you think I believe you now?”

Mr Carter shrugged. “I dunno. You’ve seen all the new rules I’ve made. They’re not very old-style Mr Carter-ish, are they? They’re more old-style Ryanish, aren’t they?”

Ryan nodded in agreement. “Yes. I don’t approve of any of them,” he said.

“And also –” said Mr Carter, pointing to Ryan – “he’s here now, agreeing with me. Why would Ryan do that?”

Dionna thought for a moment. “It could be one of his pranks.”

“One of his pranks,” said Ryan wearily, “that he’d got the most anti-prankster head teacher of all time to come in on?”

Now, Mr Carter nodded in agreement.

Dionna shook her head and sat down again, looking at him closely. “I can’t believe it, Ryan. You’re in Mr Carter’s body? Isn’t that weird? What about going to the toi—”

“We’ve agreed not to discuss that,” said Ryan.

“It’s best,” said Mr Carter.

Dionna looked from one to the other. “Are you living in his house?” she said to Ryan. (That is, Mr Carter.)

“Yep.”

“Ordered pizzas on his credit card yet?”

“Fourteen. In one night.”

“Hmm,” she said. “Maybe it is you. But … OK. What’s my mum’s name?”

“Esther.”

“Who’s my favourite singer?”

“Beyoncé.”

“Who’s my best friend?”

Mr Carter paused. Ryan looked at him, raising an eyebrow.

“Well … me. I hope. I mean him,” said Mr Carter, pointing at Ryan.

Dionna nodded. She seemed to be taking her time about what to say next.

And then she said, “But I just heard you say that the school was going to close down. Because of what you’ve done. And that you were proud of that, pleased about it!”

“Well,” said Mr Carter. “Um … yeah.”

“Even though you know that would be really, really upsetting for me because I’d have to go back to Oakcroft!”

“Oh,” said Mr Carter.

He felt a falling in his stomach. He knew this was bad and was about to say, “Thing is, what with all the changing-bodies thing, and the being-head-teacher thing, and the doing-whatever-I-like-with-the-school thing … I kind of forgot about that.” But he didn’t. Mainly because he realised it wouldn’t help much.

“And so you know what?” she said, getting up. “I’m not sure you are Ryan. Or at least, I’m not sure you are my best friend.” She was at the door by now, looking back into the room. “Because my best friend would never, ever do that to me!”

There was a chance at this point, perhaps, for Mr Carter to say, “OK, no, you’re right, I’ll do something to stop that happening.”

But he didn’t say this either. Because he could see Ryan smirking at him and he didn’t want to back down from his former triumph about the school closing. So he just looked at her and shrugged. Like a naughty, told-off little boy.

Which meant that Dionna shook her head, raised her eyebrows and went out, slamming the door.

“Oh dear,” said Ryan, still smirking.