When the assistants left, I removed my leg, clamped it to a workbench, and swung over some lighting. I studied the knee. Then I disassembled it. By midnight I had built a governor. It looked like a tin of peaches, affixed below the knee. When I flicked a little metal switch on the side, it limited the speed at which the knee could flex. I strapped it on and tried sitting. It worked. I could lower myself into a chair at normal speed with no effort. But I felt unsatisfied. Now that I thought about it, it was very primitive to have to flick a switch. The knee should figure out when to engage itself.
At three in the morning I gave up on the governor idea and connected the knee’s microprocessor to a computer so I could unpick its code. I figured I could modify this and flash new instructions. This took eight hours. In the meantime Jason and Katherine arrived and asked through the speaker if I needed help. I had them bring me snacks. Finally I loaded new code onto the chip and powered it on. The capacitor popped and died.
I stared at it. I needed sleep. With a clear head I could figure this out. I pulled on the leg, smelling stale sweat, and hobbled out. Without a functional microprocessor, the leg swung like a garden gate. The ski foot flew out in front. I made my way to the elevators with one hand touching the wall. When I reached my bunk, I pulled off the straps and threw the whole thing on the floor.
I WANTED Elaine to fetch me a cadmium battery but she was nowhere to be found. “Have you seen Elaine?” I asked Jason.
He swiveled to face me. His glasses reflected my halogen workbench light. “I thought …” He looked at Elaine’s desk. It was very clean. “Didn’t you get an e-mail?”
I rolled to my keyboard. I had lots of e-mails. I read few. I looked at the forty-character previews, and when they began, “Season’s Greetings from everyone here at …” or, “Seminars are now open for bookings on a …” it was obvious they were just noise. E-mails I needed to read began, “Didn’t you see this? You must …” or, “Your department has again failed to …” or something like that. I scrolled through my in-box. I had to sift through a lot of useless information about who wasn’t allowed to park where and why the air conditioners would be off from four to five but then I found it. It was from Human Resources. Elaine had transferred out. The e-mail didn’t say why. It just said it was thought best.
“Oh,” I said.
THAT NIGHT the cadmium battery fried the microprocessor. I had known this was a possibility but still it was disappointing. I sat at my workbench and stared at the thin wisp of smoke twisting out of the plastic knee. It was fixable. I could replace the chip. But then I would be limited by the transistors. Every time I upgraded something, something new became a bottleneck.
I pushed myself away from the bench. It was late. My problem was I was tinkering around the edges. Trying to improve it beyond the capability of its fundamental design. I was thinking like everyone else: that the goal of a prosthesis was to mimic biology.
I closed my eyes. I felt warm. I opened them, found a pad and pen, and began to write. I sketched. I filled four pages and took the leg off the table and put it on the floor to make room. I had been going about this all wrong. Biology was not ideal. When you thought about it, biological legs couldn’t do anything except convey a small mass from A to B, so long as A and B were not particularly far apart and you were in no hurry. That wasn’t great. The only reason it was even notable was that legs did it using raw materials they grew themselves. If you were designing something within that limitation, then okay, good job. But if you weren’t, it seemed to me you could build in a lot more features.
THREE WEEKS later I called the hospital. I was very excited. I had been putting this off, waiting until I was calm, but that never happened so finally I just did it. I closed the door to my bunk room and faced the wall so nothing could distract me.
“Lola Shanks, Prosthetics.”
“Hi, it’s Charles Neumann, I was in there a few—”
“Charlie! Where have you been?”
I was supposed to visit the hospital for follow-up sessions. They were mandatory, but the kind with no penalties for noncompliance. “Busy. Can I see you?”
“Yes! That would be good! I hope you’ve been keeping up your physical therapy. You’re in trouble if you haven’t. When can you come in?”
“Can you come here?” I was tapping the floor with my ski toes: tick tick tick. I made myself stop that. “I have something to show you. I want your professional opinion.”
“Um. Okay. Why not? Where are you?”
TO MEET Lola Shanks I had to go to the lobby. I hadn’t been aboveground since I discovered the bunk rooms. But she needed to be authorized. So I rode the elevator and walked the corridors. This was harder than it sounds because I was wearing the Exegesis and had never gotten around to fixing the knee. It tended to get away from me. I stuck close to walls. But I limped past hardened engineers without a single question. This puzzled me until I realized I had become pathetic.
I reached the lobby and fell into a black sofa. I pulled out my phone and looked up every few seconds to see if she was coming through the doors. I was early. I leaned forward and peered at a scale model of a mobile weapons platform that sat in a glass case on the low coffee table. Its little plaque said, CIVIL PEACEMAKER VO. 5-111. It was essentially a caravan with guns. I had been to a presentation; the idea was you towed it somewhere like a recently captured city and left it there, making peace.
“Hey!”
I jumped. Lola Shanks was coming toward me, wearing a white polo shirt, white pants, and white sneakers. Her hair was held back with a thin white headband. My first thought was she had come directly from exercising or perhaps some sort of religious event but I think it was extremely uniform fashion choices. She held out her arms. I got off the sofa, which required rocking. My unregulated ski foot flew out. Lola grabbed my hands. “Whoa! What’s wrong with the leg? It shouldn’t do that.” Before I could explain, she rolled up my pants. “What’s this?” She tapped the tin.
“I modified it.”
“You what?” By now she had exposed the knee. What was left of it. It was a half-melted empty casing. “Where’s the knee?”
“I broke it.” I felt uncomfortable. People were watching. Lola got to her feet, her brown eyes flicking between mine. “I didn’t get to say good-bye at the hospital.”
“That wasn’t supposed to be good-bye. You were supposed to come in for sessions.”
“Oh.”
“Why did you break your knee?”
“I was trying to improve it. But then I got the idea to build a new one.”
“A new knee?”
“A new leg.”
“You … what?”
“I built a prosthesis. Well. I’m still tinkering. It can be better.”
“You built a leg?”
“I’ll show you.”
“Yes,” she said. “Please.”
LOLA WAS escorted into an interview room by a guard and I returned to the sofa. While she answered questions about everyone she had ever met, everywhere she had ever been, and her Facebook profile, I flipped through the company glossy, Looking Forward. We were immunizing children in Nigeria, apparently. Lola took so long I went looking for her, and was told she was in the multiscanner. This was like a metal detector, for an advanced definition of metal. I was surprised because that should have been the fastest part of the process. You just had to stand there.
Finally Lola emerged, doing up her top button. “They swabbed me,” she said. “They swabbed my mouth.”
The guard handed her a tag. “Please wear this at all times. If you lose it, you can’t get out.”
Lola looked at me, amused, and I shook my head to tell her no, seriously. She clipped the tag to her polo shirt.
“Was there a problem?”
“Oh. No. I just have trouble with metal detectors.” She adjusted her glasses. “Forget that. Show me your leg.”
“ONE OF the problems with biological legs,” I said in the elevator, “is they can’t survive
on their own. They’re not modular. This creates isolated points of failure and dependency issues. All of which go away if you make the leg self-sufficient.”
Lola looked up from fiddling with her access badge. “Self-sufficient?”
“As in, it works by itself. It doesn’t need a warm body for fuel.”
“The Exegesis doesn’t need fuel.”
“Yes, it does. Look, I’m giving it kinetic energy right now.”
“Oh. I see.”
“Without me, it just sits there.” I glanced at her. “I mean, it’s better than nothing.”
“That’s a really good leg, Charlie.”
“For what it is—”
“Go to a public hospital. See what they’re making kids walk around in down there.” Her eyes glistened.
“Um,” I said.
“Sticks,” said Lola. “Buckets on sticks.”
“The Exegesis is also a bucket on a stick. That’s my point. It’s a terrible design. Why has nobody built a prosthesis that can walk by itself? That’s what I want to know.”
“A what?”
“It’s obvious.” I gestured with my free hand. “You put a motor in the leg.”
Lola stopped walking. “Have you put a motor in a leg?”
“Yes. No. Not a motor. Several motors. You need multiple motors to redundantly articulate the toes.” I was nervous. I hadn’t shown anybody the leg. Not complete. I had even hidden it from my lab assistants. “It’s experimental. There’s a lot I need to do. But I want your feedback. As a professional.”
Lola studied me. Then she looked around. “Where is it?”
I took her to Lab 4. It was unlikely we’d bump into my assistants; Katherine spent most of her time these days with the rats, and Jason was glued to his terminal in the Glass Room. Given the opportunity, Jason would probably stay there forever. We had much in common.
“How far down are we?” She was looking at the steel buttresses lining the walls.
“About sixty feet.” I swiped my ID tag on the door reader. The door clicked. “You need to swipe your thing here, too.”
“Why are we down sixty feet?”
“In case something goes wrong.” She followed me into Lab 4. The leg was beneath a white sheet on an insulated floor mat. It was surrounded by workbenches and lights. The sheet was because I didn’t want anyone looking at it from the Glass Room and giving suggestions.
Lola looked at me. I nodded and she approached it. I looked up: no sign of Jason. Good. Lola touched the sheet. “Can I …?”
I pulled off the sheet. Lola inhaled. I looked at her face to see if this was a good inhalation or a bad one. It was hard to tell. How did the leg appear to someone who hadn’t seen it before? Kind of spiderlike, I guessed. The upper section was a black lattice of interlocking steel. From there two silver pistons fed into a splayed eight-toed foot. I had been very proud of this but suddenly it looked creepy.
Lola walked around it three times. She stopped near the Clamp. It was still there. You didn’t decommission machinery of that caliber just because some idiot managed to lose a limb in it. “You built this?”
“Yes.”
“How did you … how did you build this?”
“You know.” I shrugged. “A little at a time.”
“It looks heavy.”
“It’s about two hundred pounds.” I pointed at dents in the floor. “It made those.”
“How do you lift it?”
“I don’t. It walks by itself.”
Lola looked at me.
“It’s not ideal. It has to remain in contact with the ground. But it can handle stairs. Those toes can get up to ten inches long. And you can’t see it, but underneath are two orbital wheels on a shifting multidimensional axis. It alternates between toes and wheels depending on the terrain.”
She walked around the leg. “What’s this?” She gestured to a series of black aluminum cases welded up near the socket.
“The processor housing. I’m not really happy with the positioning.”
“What’s it for?”
“Systems control. Data storage, GPS, wi-fi, et cetera.”
“Your leg has wi-fi?”
“It has to. Otherwise it couldn’t interface with the online path-finding API.”
Lola’s eyebrows rose.
“You shouldn’t need to tell your leg where to step. You should tell it where you want to go and let it figure out how to get there. That’s basic encapsulation.”
Lola looked back at the leg. I don’t think she really understood encapsulation. She knelt beside the leg and ran her fingers over the metal.
“I’ll put it on.” I pulled over an office chair and began unstrapping the Exegesis. It clanked to the floor and I flicked the latch that caused the new leg to ease down into a bent position. The hydraulics hissed. I positioned my stump against the socket and slid in. That was nothing special. It was just somewhere to stick my thigh.
“There are no straps?”
I shook my head. “I basically rest in it.” I steadied myself, then stood up in the leg. “Ready?” She nodded. I pressed for power. The servomagnetics started near silently. There was a line of crude buttons for simple functions and I pressed one for a short forward journey. The leg flexed in three places and glided forward. I leaned into it and performed a matching step with my biological leg. This was the clunkiest part of the whole procedure. I wasn’t happy with that. The entire time Lola was silent.
I cleared my throat. “What do you think?”
“Oh, Charlie. It’s beautiful. It’s completely beautiful.”
“Oh,” I said. “Oh. Oh. Thank you.”
AFTER I escorted Lola back aboveground, I returned to Lab 4 and sat on the floor beside my leg. I had thought Lola might like my leg, but you never knew. Her reaction exceeded all my expectations.
Then I felt depressed. It was the opposite of a logical reaction but there it was. I always felt like this at the end of a project. I would be frantic and determined and excited then sad because it was over and there was nothing left to improve. I stared at the leg. It occurred to me that I hadn’t escaped my bottlenecks. I had only pushed them back. I had made a leg that could walk by itself, which was okay, but I could see now that this was about as far as it could go. All improvement from here would be incremental, because the bottleneck was my body.
It was late. My lab assistants had left. I looked at my leg, the good one. Well. I don’t mean “good.” I mean the one I’d had since birth. I rolled up my pants and turned it this way and that. It was fat and weak and ordinary. The more I looked at it, the more it bugged me.
I PULLED my prosthetic leg apart. I didn’t mean to but once I got started I kept seeing more things I could make better. When I saw it lying in pieces I panicked about what I had done, but it was okay. I could rebuild this.
I scavenged parts from adjoining labs. I sent my assistants out for hard-to-get materials. I didn’t tell them what they were for. But they probably knew. You didn’t become a scientist if you could resist the urge to check what was under a white sheet in a spotlit laboratory. I stopped answering e-mail and performing paid duties. I did not shave. I built the leg into a new configuration that increased its mobility by half but immediately saw a better solution and stripped it down again. Some time passed. I am not sure how much. Sometimes I fell asleep in the lab and awoke in a cold puddle of drool. When I visited the vending machine, I carted away as many snacks as my arms could bear and piled them in the corner, so I could work for longer periods. The worst thing was going to the bathroom, which was all the way at the end of the corridor, near the elevators. The best part was making it there, because then I had a six- to eight-hour uninterrupted window ahead of me, and while leaning back on the toilet with my eyes closed, I would have ideas.
Messages from Lola accumulated in my voice mail. On the nights I made it to my bunk I listened to them before falling asleep. I put her on speaker and it was like she was in the room. Her messages urged me to call he
r, turning increasingly anxious. It was good to feel wanted. But I did not call her back, because my legs weren’t quite ready.
JASON BROUGHT me a set of thirty-inch coil springs. I had the leg pieces spread across my workbench. I wasn’t hiding what I was doing anymore. We had passed that point.
I realized he wasn’t leaving, and pushed up my goggles. “Yes?”
Jason’s eyes flicked across the components. “You wanted two springs.”
“Yes. Thank you.”
“It looks … it looks like you’re building two legs.”
I looked at my pieces. It was hard to deny.
“I don’t really …” said Jason. “I don’t understand why you want two.”
“Backup.”
“Oh.” He did not look convinced. Still he hung there. “Is there anything I can do for you, Dr. Neumann? Anything at all?”
I thought about this. “I would like some more snacks.”
He brought them.
I FINISHED my new legs. Well. I reached a point at which I no longer felt an urgent, clawing need to change things. I tried to stay calm but I was trembling inside. I swallowed over and over. I felt scared to look at them. It was silly. But everything about this moment seemed fragile.
I couldn’t wear them, of course. They were a set; I didn’t fit. But I could sit beside them and enjoy their presence. It was quiet, just me and them.
WHEN I was fifteen, I was almost killed by a shirtless man in a Dodge Viper. I was crossing a suburban street on my way home from school and he roared around the corner. I think he expected me to scurry out of the way, but I didn’t, because I was fifteen and valued appearing tough to strangers over remaining alive. The shirtless man clearly shared this philosophy, because his car jagged toward me. I realized I was going to die, or at least be hurt a lot. But at the last second—too late, in a car less well engineered—the Viper slid to a smoking halt.