Starring Jay Baruchel and Sarah Lind. Rated 14A.

What would happen if you could go back and change some things in the past? Not killing-Hitler things, but relatively little stuff, like saving someone from bullies, or themselves.

That's the idea behind young writer-director David Ray's Fetching Cody, which starts out as a gritty look at life on Vancouver's Downtown Eastside but turns into a fantasy involving time travel and grisly black comedy.

Things centre on a young couple living rough. By street standards, they're a happening duo. Okay, Art (Jay Baruchel) sells (and pops) pills all day and Cody (Sarah Lind) turns tricks for drug money and to pay for her day-to-day room at the Balmoral, but they're in love and actually have plans for the future-plans that get shunted aside when she suddenly gets sick, leaving Art to ponder what went wrong.

He gets a chance to trace that process back pretty far, thanks to the ministrations of his gruff guardian angel, an eccentric street veteran (played with characteristic verve by Jim Byrnes) who finds an old Barca?lounger covered in Christmas lights. He tells the lad it's a bona fide time machine, which of course turns out to be true, or true enough to catapult Art back to key points in Cody's life.

Of course, despite the creepy aspects of having an older guy show up at an all-girls school to hand you a tampon in front of your P.E. class (he's just trying to save her from a huge embarrassment), our hero gets the expected lesson: people are pretty much going to do the things people do, regardless how well-intentioned the interference.

I'm still not sure about the noble-sacrifice ending-whatever else Art may be, he's not a lazy boy-and the film's constant shifts in tone can be off-putting. Overall, though, it does raise interesting philosophical questions about our importance in other people's lives-think Groundhog Day with hints of It's a Wonderful Life and Blow. Mainly, though, Fetching Cody is an impressive vehicle for Baruchel, who comes across as a young, more soulful Jon Cryer, and TV veteran Lind, whose transformative powers are arresting.

It's also worth some shout-outs to cinematographer Paul Mitchnick, who makes Vancouver's crummiest postal code look attractively gritty, and editor Karen Porter (already notable for her complex work on A Simple Curve and The Love Crimes of Gillian Guess), who handles the time-leaping stuff with seemingly effortless finesse.