TORONTO-David Weaver had never directed anyone else's work before, but when he read Siblings he knew that had to change. "It's the most autobiographical thing I've never written," Weaver says.

Although he doesn't claim to have been involved in any murder or incest scenarios, Weaver grew up in the same sort of suburban Toronto neighbourhood as the script's functional siblings with dysfunctional parents, and he instantly related to their world. "I knew that milieu, and it's sort of similar to American Beauty or The Ice Storm, but the sense of tragic inevitability in those movies is something I was never really entirely comfortable with, because as unhappy as your life might be in those environments, you're still not in the Sudan. So what I really loved about the script and the take on suburban angst is that it wasn't self-righteous, it sort of satirized that."

Until Siblings (which opens in Vancouver on Friday, April 15) Weaver was a self-described "hyphenate"-a writer-director. His previous projects include Century Hotel, which starred enough Can Con stars to populate a Genie party, and the award-winning comic short Moon Palace.

As he sips tea on the patio at the Hotel Intercontinental just before Siblings' world premiere at the Toronto International Film Festival, Weaver explains how he fell in love with the script's black humour. He was having lunch with an old friend and had just gotten to the part of the conversation where they were gossiping about mutual acquaintances when Jackie May's name came up. His friend told him May was mostly writing cartoons (including the hit series Atomic Betty). Weaver, a fan of May's adult work, was a bit disappointed. Then the friend mentioned May's script for Siblings and said Weaver would love it.

Weaver convinced May to let him read it and, after he did, he was determined to find a way to direct it. "Here was this wonderful script with this really audacious premise and it was just sitting in the third drawer of her desk. It was with a producer, he'd dropped it, she took the script and she just put it in her drawer and went off to be a television writer."

Weaver suspects May's experiences writing for children probably provided some of the fuel for creating such a nightmarish family scenario. "Somebody said to me, "Why is there so much swearing?" And I said, 'Because it's been bottled up and waiting to come out for 10 years.'?"

The film's got a black-comedy bonus for Canadian viewers because the evil stepparents are played by two Canadian television icons-Sonja Smits (The Eleventh Hour) plays drunken mommy dearest, and Nicholas Campbell (Da Vinci's Inquest) is the abusive dad.

"I think for Sonja and Nick, the attraction of the characters is they make their workaday living being icons," Weaver says. "I can easily imagine that the first thing you want to do when you achieve that iconic status is knock it right down again."

Weaver scored another Can Con icon: Sarah Polley (My Life Without Me, Dawn of the Dead) as the foul- mouthed, levelheaded girl next door. "She is doing something that's really quite different for her," Weaver says. "And I think she proved to be very good at comedy."

Weaver says it was also a treat to work in a genre he's always loved. "We may be the first movie about kids who want to knock off their parents, but I can tell you, you can go back through film history and find some pretty evil notions in people's heads. People think that black comedy is like an invention of the late '60s or something. Or it started with Harold and Maude. But you go back to Arsenic and Old Lace, and there's a studio movie with Cary Grant about two little old ladies who systematically murder everyone they come across."

Because of the film's dark tone, Weaver was reluctant to chase after traditional Canadian film funding and approached the Canadian Film Centre, which took on the project and rushed it into production. Weaver's fear was that if a producer went after Telefilm funding, the film would lose the edge that attracted him to it in the first place. "Someone would say, "Do the parents really have to die? And the parents do have to die; that's the point of the movie. And I was worried that it would kind of get planed down.

"The parents had to be nasty and that's because it's really a fable. They're the evil stepparents, and so it's no different than Sleeping Beauty or Red Riding Hood or any of those movies that have innocent young children going off into the forest and surviving on their own. So it's a fairy-tale movie that way."

And even though it's a nasty fairy tale, Weaver is hoping for a happy ending. Aside from pitching his own projects as a writer-director, he's already working on his next movie with May.