The bomb was probably an open secret among the locals, and yet none of them said a thing. It was a wrenching betrayal of a fragile trust.
Four days after the blast, Call Sign 4-2 was back on the job. But they no longer patrolled District 2, the area where Charlie had been hit. Commanders feared emotions were still running too high.
Within days of the explosion, rumours surfaced that special forces soldiers had gone in and killed those responsible and, within a few weeks, taken out an IED factory.
No one with Joint Task Force 2, Canada's shadowy special operations force, would confirm the reports.
In late 2008, the Department of National Defence chose to stop publicizing battlefield injuries, in a stepped-up effort to deny mission intelligence to the Taliban. As a result of this - one of multiple restrictions that bind reporters who embed with the Canadian Forces there - precious little is known about many of the wounded.
In the tragic blast last year, Brad Quast got off relatively lightly. His shin was fractured. His ankle was dislocated and broken, and one foot was so badly damaged, the surgeon described what she saw as "bone salad."
Today, he hobbles around with a cane. In his dress uniform, he looks the stereotypical war veteran, except for the almost absurd incongruence of his youth. "I get a lot of weird looks," he says. "Especially when using a handicapped parking space."
His plans to join a police force or work for correctional services are on hold, and he thinks often about what happened. Sometimes there are nightmares. "I'm angry this happened to us," he says. "There's nothing to prepare you for actually getting blown up. You hear about stuff like this happening, but you never expect it to happen to you."
Barrett Fraser, another aspiring police officer, suffered a damaged back and shoulder and lacerations to his face, but his feet took the brunt of the damage, requiring more than a dozen separate surgical procedures. His dead colleagues, he says, were "like brothers" to him. "Losing them was pretty disturbing."
Fedor Volochtchik is back on his feet, mostly. His bolted-together shoulder still bothers him. He thinks about what happened almost every day. "It's like a splinter in your mind," he says. "It's always there."
Troy MacGillivray struggles with an artificial heel. He worries what will happen once the Army deems him well enough to end the contract that keeps him going now.
The blast left virtually no part of Ms. Saeed's body unscathed. Her right leg has been amputated at the knee, while her shredded lower left leg needed extensive rebuilding.
She manages a few hours daily at home with her family and fiancé, but life is still a regimen of physiotherapy and learning basic skills, such as walking with one leg. Two months ago, surgeons finally sewed her core muscles back together. There's more surgery to come. When she can focus on her future, she frets. Will she ever snowboard again or go for a hike in the hills? How will she raise children?
"I don't want to lie and pretend like I'm very optimistic or happy about this situation," she says.
Despite their ordeal, most of the surviving soldiers say they would jump at a chance to go back - either to finish their aborted tours, or to be back with comrades doing work they feel is valuable, even if it is so far from home.
"It seems more like a sense of duty now to the fallen," Cpl. Volochtchik says. "I just have to go back there at one point. Even if it is 60 years down the road, I want to go there and see."
Not Matt Chinn. For all the effort and good intentions, for all the sweat, blood and tears, he says, Canadian soldiers appear to be achieving little of lasting value. Ask him if he'd go back and he's unequivocal.
"What, are you drunk?" he says, incredulous. "As of Dec. 31, I wanted nothing more than to go home."
For Ms. Saeed, one question lingers: Would the bomb have gone off had it not been for her and Ms. Lang? "I always think about the fact that if I wasn't there, maybe they wouldn't have triggered it," she says. "I don't like thinking about that too much."
Other questions remain, too: Who decided on that sunny winter afternoon to proceed with the attack? Was the traffic jam staged to force the patrol to turn back? Whose finger was on the trigger?
For Cpl. Shier, looking for answers is a mug's game.
"You can second-guess everything that you do over there," he says. "[But]the place is so messed up, you just have to accept it."
The Canadian Press