WHAT WAS SUPPOSED TO BE a military propaganda video showing footage of U.S. Marines on patrol—protecting an Iraqi neighborhood from insurgents—now lives on the Internet, where you can see Garrett Jones's last steps as a whole-bodied man.

The 15-second clip, shot in July 2007 in the city of Karmah, is poor in quality; it's grainy, overexposed. But just beneath a line of palm trees shaking in the wind, in front of a roofless house the color of desert sand, you can make out three Marines walking in tactical formation, M-16's gripped at their waists. The lead Marine is just about to step out of the frame when the road erupts—one bomb blast, then another. Roiling plumes of pale dirt obliterate the palms, the blue sky, and Marine number three, Corporal Jones.

What you can't see is what happened afterwards—the graphic scenes of men trying to save one of their own. Often, when a bomb that powerful explodes directly beneath a man, he'll lose consciousness, which, if he survives, mercifully prevents him from reliving the events again and again. But Jones remembers every moment. His body flying through the air and landing in an irrigation ditch full of muddy water. His blood turning the water a dark shade of red. He didn't feel pain so much as heat, as if a raging fire was engulfing him from the inside out, turning his flesh into flame.

How bad am I? Bad, man. It's pretty bad. Am I gonna live? I think so.

I think so.

At which point Jones, a devout Christian who was one of the only men in his platoon who read the Bible every day, remembered that he'd forgotten to pray before he went on patrol.

Third-degree burns and shrapnel wounds on the right leg and left forearm. A golf-ball-size piece of flesh missing from his left triceps. A second chunk missing from the lat. Both eardrums blown out. Massive blood loss, requiring 14 transfusions.

Most of his injuries, while serious, were manageable. There would be scarring, rehab—big deal. His left leg, however, or what was left of it, had been blown to bits—"totally jacked," as Jones puts it. Military surgeons took one look and did the only thing they could: They cut it off. Jones was left with six inches of what amputees call "residual limb," a stump about the size of a large bell pepper. Now the corporal had to face his two biggest fears. Doctors quickly dispelled the first: Yes, absolutely, Jones would still be able to father children. Then the bad news: No, he would never again be able to snowboard, the sport he fell in love with at age nine and spent all his lunch money and allowance on as a teen. Snowboarding requires the support structure of two legs, of musculature and bones and joints that Jones no longer had, the doctors said. It was impossible. Jones spent many months mired in depression.