“That’s right,” said Molly. It didn’t sound like her at all. She smiled in a way Molly never would have, her gaze full of hate and spite. “I’m in the driving seat now. Molly’s having a little nap while I talk to you. I’ve done this before, you know, when I killed Subway Sue. Oh yes; that was me. So simple and easy, and no one even noticed. Didn’t it strike you as just a bit suspicious, her dying so suddenly? For no good reason? No? Well, you mustn’t blame yourself, Eddie. You’ve had a lot on your mind.”

She stretched slowly, luxuriously, in a not entirely human way. “It’s good to be out in the open, instead of trapped inside such a small and limited thing, watching the world from behind her eyes and making my plans. I’m not strong enough to take over yet, to subsume her mind and soul in mine. I’m more . . . potential, than actual. But you should never have brought me here, Eddie. You never should have brought me home.”

“How long have you been . . . switching her off, and taking over?” I said. My mouth was dry, but I fought to keep my voice steady.

“Not long. It hasn’t been easy, corrupting Molly from within, protected as she is by her magics and the terms of the various unpleasant bargains she made in return for power. You wouldn’t believe some of the things she’s done, and some of the things she had to promise, so she could become the wild witch of the woods. I think you suspected me, didn’t you, Eddie, but you never asked because you didn’t want to know. Still, no need to worry about that now; I will become her, and she will be just another drone serving the Masters, for as long as she lasts.”

“Why kill Subway Sue?” I said. “She was your friend.”

“Not my friend, Eddie. Dear Sue had to go, because she might eventually have realised you could use the Damnation Way to access the higher realms. And we don’t like visitors here. We really don’t.”

“Why kill Sebastian?” I said.

“That wasn’t me, sweetie,” said the thing inside Molly. “Why would I kill one of us? Now, hand over the weapon. The box. The Deplorable End. Your quest is over, your mission a failure, your war at an end.”

“I can’t do that,” I said. “Molly wouldn’t want me to.”

A silver blade appeared in Molly’s hand, and she put the edge to her own throat. It was the arthame, its supernaturally sharp edge already cutting the skin so that blood coursed down her neck. Molly smiled, her eyes full of a vicious glee. “Do as you’re told, little human, or I’ll cut my throat. And after she’s dead, I’ll take the box from you anyway.”