By January 2008, former Marine gunnery sergeant Matthew Hevezi was just trying to hold on. His depression, which he likened to quicksand, had him by the balls, and each day he was being pulled down deeper. Nothing, not even sleep, came naturally anymore. He used medication to put himself out at night and sheer willpower to get up in the morning. Dreams from the night before leaked into the day—young Marines beheaded or impaled on spikes, he himself trapped in a car under the ocean, his 11-year-old boy caught and killed in crossfire—dreams that appalled and exhausted him. He barely ate. He was constantly cold. His only foothold, the bit of steel inside: He had to stay alive for his two sons.

That winter afternoon when his wife saw him standing silently in the bedroom doorway, she turned o` the TV and asked what was wrong. "Time to go to the hospital," Matt said. This would be his fourth trip to the psych ward, and no, he didn't need her to drive him. He'd already called his "li'l brothers"—former Marines major Gamal Awad and sergeant Justin Inabinette—and they were standing by, ready to take him to the VA in San Diego. They'd all been in and out of psych wards; they knew the drill.

Matt showed up at Gamal's front door in Temecula, pain printed so sharply on his face that it seemed to have frozen it. He said nothing to Gamal, just stared unblinkingly into his eyes. To anyone else, it would have been unsettling, but Gamal had long since lost the ability to be unnerved. In a crisis, his heart shut down and his brain switched into action mode, a useful quality if it weren't for the fact that Gamal lived every day in a state of crisis, so he hardly felt anything anymore, his heart a tomb, and he planned every trip out of the house, even taking his dogs for a walk, as if he were executing a military mission. Gamal saw Matt and began issuing orders. "Justin drives," he said. "I'm shotgun. Matt, you're in the back." His brisk, almost overly efficient manner was partially for Matt's benefit, "to let him know we've got him, we'll carry him now."

They could've put Matt in the trunk, for all he cared. "I was fucking flatlined," he says.

Gamal had already prepared his car for the sixty-mile drive to San Diego—cell phone on the dashboard, camera facing forward, ready to record any problem that might arise, GPS with their destination punched in. Camp Pendleton Marine base, where they had all served and where all three were discharged against their will, lay close by. Neither Gamal nor Justin asked Matt a single question. Theirs is a "probe-free relationship," as Gamal calls it. In fact, if there were any rule to their friendship, it would be just that: No probing. VA doctors, military shrinks, curious civilians with nothing at stake ask questions. They stick a shovel in your brain: How does it feel? Gamal put the radio on, killing the silence.

When they arrived at the VA, Gamal told Justin where to park. Gamal had been here many times before—not inside the hospital but sitting in this parking lot, trying to will himself out of the car and into the emergency room to ask for help. He could never do it, though; he didn't believe there was any treatment that could fix him. As he led Matt toward the emergency-room doors, a nonsensical thought ran through his brain: There are many ways to dissect a frog, but the frog is still dead.

They walked up to the intake window. There were questions, and Gamal answered for Matt, occasionally turning to him: "Is that accurate? That pretty close?" Then they sat waiting for a doctor. "He seemed catatonic," Gamal remembers. "Nothing behind the eyes."

When the doc arrived, Gamal swung to his feet and, taking one last look at Matt, walked away. He said nothing, not even good-bye. "What can you say? 'I'm here for you, buddy'? He already knows that. 'Tomorrow will be a better day'? There's nothing to say but 'Things are fucked-up.' And he knows things are fucked-up and I know things are fucked-up, so…"

Many months later, once we'd all gotten to know one another, after hundreds of phone calls and e-mails and interviews, Justin phoned me at 2 a.m. to say, "You know what you should call your story, the story of me and Matt and Gamal? 'The Lost Convoy.'"

*****

I met Gamal first. Three years ago, a veterans' advocate called to tell me he knew of a Marine major who was willing to go on the record about suffering from PTSD and, after being charged with misconduct, had been drummed out of the Corps. He didn't have to say anything more. Marines don't suffer from PTSD; a private or lance corporal may occasionally, reluctantly, suffer from "combat stress." But Marine officers? They don't even get head colds.

The Marines, or Many Americans Running into Endless Shit, as they refer to themselves, are notoriously stoic. From the moment they enter boot camp, they're taught that nothing is stronger than the will, which can push the body through heat, mud, fear, exhaustion, and pain. The Marines are the "first to fight," the "tip of the spear"; they take the land, and then the Army rolls in and holds it. They call themselves the shit's shit; other soldiers call them bullet bags and bullet sponges.

"When you earn the title Marine, the expectations of toughness are inherited," Matt says. "As soon as you put the uniform on, you're expected to be a Marine, and Marines are not weak—physically or mentally. The culture doesn't allow it." A broken Marine is not only useless, he's morally suspect—a malingerer, a nonhacker, a shitbird, a broke dick, a 10-percenter, a light-duty commando, one of the sick, lame, and lazy. As Gamal puts it: "You have a mental illness? Get a straw and suck it up."