“Did you see my trousers in the wolf’s mouth?” he says. “I did the switching hex and it worked even though my wand is broken! That’s potent magic, guys, but I did it!” He’s so delighted he wriggles around, making our raft tip. Water splashes over my already frozen feet.

As Win chatters on, I manage to work out that when Win did the spell my fur onesie instantly swapped places with his trousers. Rose has helped me back into my onesie, but it’s soaking and, if anything, it’s made me even colder. I lie back, shivering, and I listen to Win boast.

“I mean, I’m a bit cold now and I’m in my underpants, but that’s the best magic I’ve ever done in my life. I bet Mitch couldn’t do it!”

I know I should say something, thank him for saving my life, but right now I’m too exhausted.

“Arthur’s cold,” says Rose, giving me a prod. “He’s stopped talking.”

“Leave this to me,” says Win, his voice brimming with newfound confidence. Through half-frozen eyelashes I see him take out his broken wand and point it at me.

“Wait . . .” I whisper, but he’s already begun muttering, his eyes half-closed.

“MISTER FLAMBAYGO!” he booms, his voice echoing around us.

A golden bubble starts to grow out of the end of his wand. It looks like it’s being slowly inflated. It lights up the tunnel we’re floating through and I see that the ice ceiling isn’t far above our heads. Water swirls around us and the sides of the tunnel are smooth. We couldn’t get off this raft, even if we wanted to.

Still holding his wand and the golden light up high, Win leans close to me and whispers, “The magical heat of Mister Flambaygo will warm you to the core, Arthur.” Then he wiggles the wand, making the ball teeter for a moment before dropping into my lap.

It’s like a balloon of fire.

“Aaaagh!” I scream, jerking upright. I scoop up the burning sphere and toss it in the air. It lands on my shoulder, making me scream again, then it rolls down over me before coming to a stop in the middle of the raft. For a second it sits there, then it melts a hole through the ice before disappearing into the water with a hiss.

“Imaginary,” whispers Win.

“And really, really, hot,” I say, pressing my burnt fingers down on the ice.

“Don’t be so ungrateful, Arthur,” says Rose. “Look, ‘Mister Flambaygo’ even dried your onesie.”