Mr Mollusc, avoiding my eye, grasps the wheelchair handles. With a grunt of effort, he turns the contraption around and pushes it creakily across Dolphin Square and into the wakening town.

My legs are a bit wobbly as I head back inside.

“Are you OK?” says Violet.

I manage a grin. “I don’t think I’ve ever been OK-er.”

And so that’s it. Just about.

There’s a bit that comes next where cakes are brought out, and more hot chocolate is made, but I’m sure you can imagine all that for yourself. It’s quite the little party.

A short while later, I manage to get Vi alone again. We’re in the shop window, in front of the mermonkey. Its hat is held out to us, just a finger away. We both look up at its horrid grinning chops, and I can’t help wondering if everything that happened to us would have happened differently if the mechanical beast had chosen a different book for Vi, back when she first came here. Or would it have all happened like this anyway, whatever the book? I suppose there’s no way to know.

“So what happens now?” says Violet. “I think this is the end of the story.”

“Could be,” I say, with a shrug. “Or could be it’s just the beginning.”

Violet gives a shrug of her own. “I suppose I’ll have to go. Back to Great-Aunt Winniegar.”

“Or,” I blurt out, “you could not go! It kind of feels like this is your place now, Violet. It kind of feels like there’s room in my cellar for two. I kind of wonder if maybe the Grand Nautilus Hotel could do with a second Lost-and-Founder, only we’d be more like detectives, in a kind of partnership, together, detecting cases and finding lost things and making everything all right again, one mystery at a time. Or … or something! I haven’t worked it all out yet, but I’m, er, kind of wondering if you’d like that.”

Then I stop, because all this came out in a rush and I can tell I’ve gone a bit red.

“It’s funny,” says Vi with a smile. “I kind of had a similar thought but didn’t know how to ask.”

I grin. “Of course, I can’t promise another adventure like this one,” I say. “Maybe this is the only interesting thing that will ever happen to us.”

There’s a purr, and we both look down to see that Erwin the cat has appeared, and is entwining himself around our legs.

“Hello, Puss,” says Vi.

But Erwin says nothing.

Violet picks him up and holds him in her arms. He looks her in the eye. Then he reaches out a paw and taps the rim of the mermonkey’s hat.

Its eyes light up.