Free ARM by Larry Niven

partner.”
    “Sounds typical.”
    “Could he be telling the truth?”
    “I'd say he's lying. Doesn't make him a killer, though.”
    “No. What about Ecks? If he didn't know Peterfi was involved, he might have tried the same thing. Does he need money?”
    “Not hardly. And he's been with Uncle Ray for longer than I've been alive.”
    “Maybe he was after the exemption. He's had kids, but not by his present wife. He may not know she can't have children.”
    “Pauline likes children. I've seen her with them.” Porter looked at me curiously. “I don't see having children as that big a motive.”
    “You're young. Then there's Pauline herself. Sinclair knew something about her. Or Sinclair might have told Ecks, and Ecks blew up and killed him for it.”
    Porter shook his head. “In red rage? I can't think of anything that'd make Larry do that. Pauline, maybe. Larry, no.”
    But, I thought, there are men who would kill if they learned that their wives had gone through a sex change. I said, “Whoever killed Sinclair, if he wasn't crazy, he had to want to take the machine. One way might have been to lower it by rope...” I trailed off. Fifty pounds or so, lowered two stories by nylon line. Ecks's steel and plastic arm ... or the muscles now rolling like boulders in Porter's arms. I thought Porter could have managed it.
    Or maybe he'd thought he could. He hadn't actually had to go through with it.
    My phone rang.
    It was Ordaz. “Have you made any progress on the time machine? I'm told that Dr. Sinclair's computer—”
    “Was wiped, yah. But that's all right. We're learning quite a lot about it. If we run into trouble, Bernath Peterfi can help us. He helped build it. Where are you now?”
    “At Dr. Sinclair's apartment. We had some further questions for Janice Sinclair.”
    Porter twitched. I said, “All right, we'll be right over. Andrew Porter's with me.” I hung up and turned to Porter. “Does Janice know she's a suspect?”
    “No. Please don't tell her unless you have to. I'm not sure she could take it.”
* * * *
    I had the taxi drop us at the lobby level of the Rodewald Building. When I told Porter I wanted a ride in the elevator, he just nodded.
    The elevator to Raymond Sinclair's penthouse was a box with a seat in it. It would have been comfortable for one, cozy for two good friends. With me and Porter in it, it was crowded. Porter hunched his knees and tried to fold into himself. He seemed used to it
    He probably was. Most apartment elevators are like that. Why waste room on an elevator shaft when the same space can go into apartments?
    It was a fast ride. The seat was necessary; it was two gees going up and a longer period at half a gee slowing down while lighted numbers flickered past. Numbers but no doors.
    “Hey, Porter. If this elevator jammed, would there be a door to let us out?”
    He gave me a funny look and said he didn't know. “Why worry about it? If it jammed at this speed, it'd come apart like a handful of shredded lettuce.”
    It was just claustrophobic enough to make me wonder. K hadn't left by elevator. Why not? Because the ride up had terrified him? Brain to memory: dig into the medical records of that list of suspects. Claustrophobia. Too bad the elevator brain didn't keep records. We could find out which of them had used the boxlike elevator once or not at all.
    In which case we'd be looking for K 2 . By now I was thinking in terms of three groups. K 1 killed Sinclair, then tried to use the low-inertia field as both loot and alibi. K 2 was crazy; he hadn't wanted the generator at all, except as a way to set up his macabre tableau. K 3 was Janice and Drew Porter.
    Janice was there when the doors slid open. She was wan, and her shoulders slumped. But when she saw Porter, she smiled like sunlight and ran to him. Her run was wobbly, thrown off by the missing weight of her arm.
    The wide brown circle was still there in the grass, marked with white chalk and the yellow chemical that picks