I ran. I punched the control lever. Mighty Chair’s wheels spun briefly before gaining traction. Then I burst forward. I started racing down the curving ramp. As I reached the first corner, I hunched my shoulders and shifted my weight, leaning into the turn as if I were cutting through packed snow on the slopes. I could hear the SUV turning. There was no room for it to turn without shifting back and forth, so the driver was making his own room, banging and smashing cars out of his way, pushing them into the retaining walls.

Mighty Chair wasn’t aerodynamic, but it did hold a line and cornered well, for a wheelchair. Y’s imagination was paying off. When he’d built it, he’d been playing mad inventor, envisioning video-game scenarios, James Bond escapes, neither of us believing any of that would become necessary. Or that one winter afternoon it might save my life. I had just reached the third level when I heard the SUV crashing down behind me. Its wheels shrieked as the driver drifted into the corners, bouncing off walls like a pinball bouncing off bumpers, but it kept coming.

Incredibly, I heard Cher’s stern voice warning me, “Rollie, Mighty Chair wants me to tell you this speed is not safe.”

Sorry, Cher. Y had added an auxiliary motor to Mighty Chair, but I wasn’t going to outrun an SUV. I twisted to see where he was, and as I did, I had the odd thought that Y should add a rearview camera. There were several nifty tools already built into the chair that might have helped, like spewing silicone, but I had dismissed that as another one of Y’s Bond jokes and hadn’t bothered to memorize the program code. I could slow down and ask Cher to find it, but the one thing I could not afford to do was slow down.

I whirled around the next bend, trying to hug the inside wall. I’d run several wheelchair races, so I had some idea how to maximize and control my speed. But racing chairs were designed for speed. Mighty Chair was the real thing. Gravitational forces buffeted me from side to side and I was struggling to stay in the seat. I slipped my left arm under the armrest and curled my fingers over the front of it, holding tight.

The SUV was gaining; I heard metal crunching and glass shattering as it bounced off parked cars and slammed into a wall, then a long shriek as a metal piece sliced into the cement. It must have dropped the muffler because suddenly the engine got a lot louder. And a lot closer. A beast was hunting me.

When you’re running for your life, you don’t think, you react. Everything I did was pure instinct. I’d never ridden a wheelchair downhill at maximum speed—in fact I had never heard of anybody who had—but turn by turn I was figuring out how to survive. I was careening from side to side, shifting my weight from side to side to maintain my balance as if I were slaloming downhill. Cher was making all types of warning sounds. This was Chair to the max. I guessed I had two turns, about 250 feet, and a tollgate to get through before the SUV hit me. In that instant my mind flashed back to the last time I’d been sprinting to save my life. I could see that open door in front of me. I could see kids racing in front of me. I could see that bright sunlight framed in that doorway. I never got there. The house had collapsed around me. Somehow, though, I’d gotten a second chance. Make it or die.