I shake myself. Bad things coming, screams one of my selves from the back of my head. Hide!

I don’t know how long I lie there, quivering in fear and loneliness — and wishing Petruchio were around, just for the comfort of his presence — but it’s too long. Then there’s a brief click as the wheels jolt over a join in the rails, and it startles me out of my paralysis. If She has sent her killers after me, what will they do? They’ll have followed me aboard the train, and they’ll have located my compartment, and they’ll want to ensure a clean getaway after they kill me—

Click-click go the rails. I blink. Are we slowing? It doesn’t stop until New Chicago, I remember. So they’ll make their move before we arrive, burst through the door with knives drawn—

(I’m on my feet, gun in hand as the thought sinks in.)

Or they’ll arrange for something to happen after they leave the train at New Chicago—

My nostrils flare as I sniff at the gas mix in the cabin. It’s rich, distinctly headier than usual. I plugged myself into the train power loop while I slept, and now I unplug the umbilical, letting it retract back into the bunk. Sniff. Smells like… smells like free oxygen. Which is silly. The Great Southern Railway Corporation doesn’t let oxygen circulate freely except in first-class compartments: it etches the carriage work, and besides, it costs good money. Oxygen?

Oxygen. A terrible memory bubbles up from some dark well of personal horrors — the collective nightmare of my lineage, perhaps, or a dead soul I wore many years ago — of a body stumbling, wreathed in flowing blue flames that seem to burst like clouds from every orifice. Suicide on Titan, I remember. He’d overdosed on oxygen, soaking in the stuff, then calmly walked through a door onto the surface and, standing on a sandy beach of ice crystals by the edge of a methane sea, he’d bridged the terminals of a small battery with one fingertip. (Saying he loved me — no, that was definitely somebody else’s nightmare, surely? Not mine, or Juliette’s.) Oxygen is a terrible substance, almost as dangerous as water. It’s alright in some circumstances, but in a railway carriage with fittings made from cheap metal sheeting, built to cross the sands of Mars, it can be deadly…

I open the door delicately, trying not to jar anything. Glancing either way up the dim-lit passage, I see no sign of other wakeful passengers. I sniff again. The faint tang of the air reminds me of Earth, albeit drier and much cooler. One of my love’s dead Creators could breathe here, I think. I check the time. I think we are due to arrive in New Chicago soon — ten minutes?

I hear a faint hissing noise overhead, coming from the air vents. I sniff again. Yes, it’s the telltale stink of oxygen. My hair tries to stand on end in another of those strange biomimetic reflexes. I glance both ways, undecided. I can see them in my mind’s eye, a pair of black-clad dwarfs, tittering quietly as they splice their canisters of diamagnetic death into the air-conditioning pipes. They’ll be at one end of the car, of course, but which end? When the train stops, they’ll be ready. They’ll leave an igniter behind as they leg it, waiting in the chilly, heady air as the train leaves New Chicago’s platforms behind.

I lean against the brightly polished magnesium door and try to slow down my gas-exchange cycle. Breathe slowly, I tell myself. I glance down at the scuffed, black, carbon-fiber carpet. I come from Earth. It’s not as if I haven’t seen naked flames before, is it?

The corridor runs fore and aft along the carriage. Doors at each end give access to the baggage racks and platform air locks. I sidle toward the rear door, feeling the carriage sway around me. It’s decelerating noticeably, and I feel gossamer-light as I approach the end of the corridor. There’s a window in the door, so I crouch as I near it, slowing and rising to put my ear to the panel.

“Ten minutes,” says a familiar voice. “That should be enough. I’ll fuse it for five minutes after departure.”

There’s a muffled reply. I don’t wait around. My spine’s prickling with tension. Some bloodthirsty part of me wants to burst through the door and rip and stomp and tear, but common sense says I’d be crazy to do that. There are at least two of them and they’re armed. So I stand up slowly and begin to back away, down the corridor.

Then the door opens.

Reflexes I didn’t know I had take over. My perceptions narrow down to a brilliant sequence of beads on a wire. Brief impressions remain: my right hand coming up, the Swiss army pistol pointing like a finger, left hand rising to cradle it as if I’ve done this a thousand times before. The small black-clad homunculus, explosions of lace at wrists and throat, raising his hand and pointing something stubby at me. The slow squeeze on the trigger, far too slow — He’s going to shoot first — then the bang, terrifyingly loud in the confined space, and the flash. A second shot, and a third. Something plucks at me, déjà vu flashback to a fight outside a graveyard — but it’s just my jacket, and I fire again, and he’s falling slowly, drifting down as I dive toward him, trying to stay low before the second dwarf tries to shoot me.

Then I’m halfway through the doorway, and the second dwarf is nowhere to be seen. I twist around, and as I glimpse the outside world sliding slowly past the window in the platform air-lock door, he lands on my left shoulder like a ten-kilogram bundle of malice. It’s a reaction shot. He bounced off the ceiling, aiming for my head, but I was moving too fast. He’s got his arms around my neck, and he’s biting my ear. I flick the revolver cylinder aside and whack at him using the skeletal butt as a knuckle-duster. I’m terrified he’s going to gouge at my too-big eyes, and this lends extra force to my blows. Something rips across my cheekbone, and there’s a searing pain in my ear; then I can see again, and I’m free. He bounces across the room, and I turn toward the sound—

“Manikin robot bitch! I kill you deadly!” He’s leaning against the locked platform door, something small and cylindrical held in his clenched hands. He glares at me with burning hatred. Another of Stone’s brothers.

I roll my eyes. “You won’t, because you’ll be dead, too.” He’s got one finger poised over a button. I smell the acrid scent of free oxygen: heady, virulent and corrosive. “That would be a pile of no fun at all, wouldn’t it?”

“Robot.” They get repetitive when they’re angry, one of me chirps up with a nasty thrill of glee.

I move sideways very slowly, putting the wall of the baggage compartment at my back. I try not to think about what it’s made of — lovely metal, shiny, lightweight, strong, and utterly unsuitable for an oxidizing atmosphere. “Do you really want to die? I’m open to alternatives…”

“Why not?” He smirks. “I gave my soul to a brother before I got on the train. Oh, I almost forgot. Your sister sends her regards.”

Oh really? I freeze my face, then carefully flare my nostrils and raise my brows, composing a mask of deep contempt. “What’s your name, little man?”

“I’m Jade.” He titters. “So pleased to meet you, Freya.”

Shit. I remember Jeeves’s earlier words: My dear, I fear we are in trouble. “Pleased to meet you, Jade,” I say lightly. “Shame about the circumstances. ” (Me holding a gun on him, him holding an igniter on me, both of us in a magnesium tube stuffed with free oxygen.)

I can feel something trickling down the side of my neck. “Let me assure you, being remembered by a sib isn’t the same as being alive. So let me make you an offer. This train is stopping. I intend to get off it, and I suggest that you stay on it. Stay out of my sight, and neither of us needs to die.”