“Nothing we can do,” said Natasha. Her face was flushed and perspiring heavily, too. “If we lose control of this train, even for a moment, it’ll turn on us. But don’t worry. This really is quite exhilarating.”

“Yes,” said Happy. “Lovely.”

Melody moved to sit at JC’s other side, so she could lean in close and whisper. “They’re spending too long locked together. They’re already acquiring each other’s speech patterns. God knows what information she’s picking out of his brain, or what nasty habits he’s picking up from her. We need to separate them while we still can.”

“We can’t do anything until the train gets us where we’re going,” said JC. “You have to work your instruments, find us a way to fight back.”

“Oh right; load everything on me.”

“We all do what we have to,” said JC. “Now concentrate. The first thing we need is some idea of who or what our unseen enemy is. We need a name, an identity, some indication of its powers and limitations. And, hopefully, its weak spots. Next, we need to nail down its exact physical location in the Underground. It used the energies created by Kim’s murder to open a portal onto this plane, and now it’s using her continued ghostly existence to maintain its presence in our world. That makes it vulnerable. So we have to find and face the Intruder, hurt it enough to weaken it, then break the bonds that connect it to Kim so we can drive it out of our world and slam the door shut behind it.”

“Oh,” said Melody. “Is that all?”

“Isn’t he wonderful?” said Kim, beaming. “He’s got a plan for everything!”

“Not necessarily,” said Melody. “It could be that the only way to banish the Intruder from our world . . . is to remove the focal point that holds this haunting together. Which is you, Kim. Your existence makes the Intruder’s presence possible. To get rid of him . . .”

“We don’t know that for sure,” said JC. “There’s a lot of things we don’t know for sure yet.”

“But could you sacrifice her?” said Melody relentlessly. “If that’s what it takes?”

“He won’t have to,” said Kim. “I’ll do whatever’s necessary to save my world.”

“Isn’t she wonderful?” said JC.

“You poor damned fools,” said Melody. “There’s no way this can have a happy ending.”

She turned her back on JC and Kim and wouldn’t look at them for the rest of the journey.

The train brought them back to the southbound platform without incident. The car doors opened, a little blood leaked out, and everyone disembarked. Melody ran straight to her waiting equipment and did her best to embrace them all at once.