Written and Directed by Megan Park | 89 min | ▲▲▲▲△

For me there’s little better than a genre picture — in this case a coming-of-age movie with just a touch of fantasy — that works within the tropes but still ends up delivering something fresh and surprising. This is what we have here, a Canadian/American indie from actor-turned-director Park (The F Word/What If) that, while its ambitions are modest, is a complete delight — funny, affecting, and entirely unexpected. Don’t be put off by the irreverent title.

Eighteen-year-old Elliott (Maisy Stella) is spending her summer at the family’s cranberry farm in the lake district, the Muskokas, north of Toronto, before going to U of T. She’s got about three weeks before leaving and is doing a lot of partying with her pals. While spending the night camping on an island she and her two best friends, Ruthie (Maddie Ziegler) and Ro (Kerrice Brooks), take a fistful of ‘shrooms. Ruthie and Ro wander off into the dark and out of nowhere an older woman (Aubrey Plaza) shows up. She’s also Elliott, but at age 39.

What is Elliott the Elder up to and why and how is she visiting? That’s a little unclear — after all, this is a drug trip. But she does convey a few, intriguing details of her future world and a little wisdom, most important being that Elliot The Younger needs to avoid a fellow named Chad. That shouldn’t be too difficult since she’s queer and has never been into men, but then who should she meet but a Chad (Newfoundlander Percy Hynes White) who’s working on the farm.

It’s not all about them, though. Scenes where Teen Elliott spends more time with her family — on the advice of her older self — are sweet and moving, especially with her mother (Maria Dizzia), and two younger brothers (Seth Isaac Johnson, and Carter Trozzolo).

There’s about a dozen ways this material could be mishandled — in the humour, the identity politics, the family dynamics, the fantasy/science fiction elements, the casting — but Park has a light touch with all of it, and has chosen a fantastic lead: Stella is simply perfect, a teenaged protagonist who we love even when she makes bad decisions, and the script is clever enough to allow the wisdom to go both ways — the elder can also learn from her younger self.

I’m also loving the trend — if you could call two features a trend — of movies shot in cottage country north of Toronto. (The other recent one I’m thinking of is Anna Kendrick in Alice, Darling.) Park and her DP Kristen Correll shoot the area as an exquisite summery paradise.

Plaza is typically terrific — and seeing her this weekend in Megalopolis and on TV in Agatha All Along it feels like she’s the biggest star in Hollywood right now. She’s really only on board in support, and physically different enough from Stella to earn a declamatory comment in the script, deftly enough to undercut any concern around continuity or those inevitable corkscrew time travel scenarios. This movie couldn’t care less about explaining the hows or whys, and more power to it.