It was Cassandra! She'd ducked into one of the other rooms, and lain in wait for me. Pickover was no detective; he had completely missed the signs of his quarry no longer being in front of him — and I'd had Pickover's body blocking my vision, plus the echoing bangs of his footfalls to obscure my hearing. I could see my own chilled breath, but, of course, not hers.
I tried again to call out to Pickover, but all I managed was a hoarse croak, doubtless lost on him amongst the noise of his own running. I was already oxygen-deprived from exertion, and the constricting of my throat was making things worse; despite the darkness I was now seeing white flashes in front of my eyes, a sure sign of asphyxiation. I only had a few seconds to act—
And act I did. I crouched down as low as I could, Cassandra still on my back, her head sticking up above mine, and I leapt with all the strength I could muster. Even weakened, I managed a powerful kick, and in this low Martian gravity, I shot up like a bullet. Cassandra's metal skull smashed into the roof of the corridor. There happened to be a lighting fixture directly above me, and I heard the sounds of shattering glass and plastic.
I was descending now in maddeningly slow motion, but as soon as I was down, Cassandra still clinging hard to me, I surged forward a couple of paces then leapt up again. This time, there was nothing but unrelenting bulkhead overhead, and Cassandra's metal skull slammed hard into it.
Again the slow-motion fall. I felt something thick and wet oozing through my shirt. For a second, I'd thought Cassandra had stabbed me — but no, it was probably the machine oil leaking from the bullet hole I'd put in her earlier. By the time we had touched down again, Cassandra had loosened her grip on my neck as she tried to scramble off me. I spun around and fell forward, pushing her backward onto the corridor floor, me tumbling on top of her. Despite my best efforts, the flashlight was knocked from my grip by the impact, and it spun around, doing a few complete circles before it ended up with its beam facing away from us.
I still had my revolver in my other hand, though. I brought it up, and, by touch, found Cassandra's face, probing the barrel roughly over it. Once, in my early days, I'd rammed a gun barrel into a thug's mouth; this time, I had other ideas. I got the barrel positioned directly over her left eye, and pressed down hard with it — a little poetic justice.
I said, “I bet if I shoot through your glass eye, aiming up a bit, I'll tear your artificial brain apart. You want to find out?”
She said nothing. I called back over my shoulder, “Pickover!” The name echoed down the corridor, but I had no idea whether he heard me. I turned my attention back to Cassandra — or whoever the hell this really was. I cocked the trigger. “As far as I'm concerned, Cassandra Wilkins is my client — but you're not her. Who are you?”
“I am Cassandra Wilkins,” said the voice.
“No, you're not,” I said. “You're a man — or, at least, you've got a man's mind.”
“I can prove I'm Cassandra Wilkins,” said the supine form. “My name is Cassandra Pauline Wilkins; my birth name is Collier. I was born in Sioux City, Iowa, on 30 October 2079. I immigrated to New Klondike in July 2102. My citizenship number is—”
“Facts. Figures.” I shook my head. “Anyone could find those things out.”
“But I know stuff no one else could possibly know. I know the name of my childhood pets; I know what I did to get thrown out of school when I was fifteen; I know precisely where the original me had a tattoo; I…”
She went on, but I stopped listening.
Jesus Christ, it was almost the perfect crime. No one could really get away with stealing somebody else's identity — not for long. The lack of intimate knowledge of how the original spoke, of private things the original knew, would soon enough give you away, unless—
Unless you were the spouse of the person whose identity you'd appropriated.
“You're not Cassandra Wilkins,” I said. “You're Joshua Wilkins. You took her body; you transferred into it, and she transferred—” I felt my stomach tighten; it really was a nearly perfect crime. “And she transferred nowhere ; when the original was euthanized, she died. And that makes you guilty of murder.”
“You can't prove that,” said the female voice. “No biometrics, no DNA, no fingerprints. I'm whoever I say I am.”
“You and Cassandra hatched this scheme together,” I said. “You both figured Pickover had to know where the alpha deposit was. But then you decided that you didn't want to share the wealth with anyone — not even your wife. And so you got rid of her, and made good your escape at the same time.”
“That's crazy,” the female voice said. “I hired you. Why on — on Mars — would I do that, then?”
“You expected to the police to come out to investigate your missing-person report; they were supposed to find the body in the basement of NewYou. But they didn't, and you knew suspicion would fall on you — the supposed spouse! — if you were the one who found it. So you hired me — the dutiful wife, worried about her poor, missing hubby! All you wanted was for me to find the body.”
“Words,” said Joshua. “Just words.”
“Maybe so,” I said. “I don't have to satisfy anyone else. Just me. I will give you one chance, though. See, I want to get out of here alive — and I don't see any way to do that if I leave you alive, too. Do you? If you've got an answer, tell me — otherwise, I've got no choice but to pull this trigger.”
“I promise I'll let you go,” said Joshua.
I laughed, and the sound echoed in the corridor. “You promise? Well, I'm sure I can take that to the bank.”
“No, seriously,” said Joshua. “I won't tell anyone. I—”
“Are you Joshua Wilkins?” I asked.
Silence.
“Are you?”
I felt the face moving up and down a bit, the barrel of my gun shifting slightly in the eye socket as it did so. “Yes.”
“Well, rest in peace,” I said, and then, with relish, added, Josh.”
I pulled the trigger.
The flash from the gun barrel briefly lit up the female, freckled face, which was showing almost human horror. The revolver snapped back in my hand, then everything was dark again. I had no idea how much damage the bullet would do to the brain. Of course, the artificial chest wasn't rising and falling, but it never had been. And there was nowhere to check for a pulse. I decided I'd better try another shot, just to be sure. I shifted slightly, thinking I'd put this one through the other eye, and—
And Joshua's arms burst up, pushing me off him. I felt myself go airborne, and was aware of Joshua scrambling to his feet. He scooped up the flashlight, and as he swung it and himself around, it briefly illuminated his face. There was a deep pit where one eye used to be.
I started to bring the gun up and—
And Joshua thumbed off the flashlight. The only illumination was a tiny bit of light, far, far down the corridor, spilling out from the torture room; it wasn't enough to let me see Joshua clearly. But I squeezed the trigger, and heard a bullet ricochet — either off some part of Joshua's metal internal skeleton, or off the corridor wall.
I was the kind of guy who always knew exactly how many bullets he had left: two. I wasn't sure I wanted to fire them both off blindly, but—
I could hear Joshua moving closer. I fired again. This time, the feminine voice box made a sound between an oomph and the word “ouch,” so I knew I'd hit him.
One bullet to go.