Watch one of those videos of would-be suicide bombers promising fiery death to the great Western serpent or whatever, and it’s hard not to see the future terrorists as pure evil. But watch the b-roll from the same videos. When the terrorists don’t think the camera’s on, they become real people — joking, laughing, relaxed.

“It doesn’t conform to type, does it?” director Chris Morris asked a London Guardian reporter last year while they watched a 2000 video of 9/11 mastermind Mohammed Atta clowning for the camera between serious takes. “These aren’t cold, reptilian killers. They’re dicking about with a hat.”

That’s where Morris begins Four Lions, which won the Best Comedy award at the BAFTAs in January. Four wannabe-terrorists in the northern English town of Sheffield are shooting the video they hope will be shown after they’ve martyred themselves, but they keep bungling their lines, they bicker with each other, and the camera keeps falling off the kitchen pot they’re using as a tripod.

Morris uses this behind-the-scenes perspective to humanize otherwise one-dimensional terrorists. Omar, the group’s ringleader, lives in a nice house with a beautiful wife and a loving son. Hassan joins the gang to appear strong and serious.

But the film also skewers their fanaticism. Barry is a paranoid idiot who eats his phone’s SIM cards to avoid government detection. Fessal is training crows to become kamikaze bombers. When the latter accidentally blows himself up in a pasture, the others assuage their own guilt by declaring him a martyr but then begin to wonder if you can really be a martyr when you’ve only killed an innocent sheep.

Morris doesn’t forget the stakes here, though. Toward the end, the film grows jaw-droppingly did-they-just-do-that? dark, as the boys infiltrate the London Marathon wearing bomb belts and furry costumes. These last 30 minutes are painfully funny, or hysterically tragic. It’s hard to decide.

The film continues the discussion in the DVD extras, which include an exploration of what it’s like to grow up as an English Pakistani and an interview with an accused terrorist in detention. (Rated R)