Cornelia Duryée’s Portal Runner is a small-scale science-fiction family film with a big vision. Nolan (Sloane Morgan Siegel) is a 15-year-old who bursts out of a shimmering mirror into a darkened bedroom, pursued by a leather jacket-clad man with a burnt face and darkened complexion. Nolan quickly fashions a lethal trap and springs it on the monster, to no effect. He keeps running, eventually hiding in a closet only to be found by … his sister, Mae (Elise Eberle), who is completely oblivious to her brother’s plight. What is Nolan’s deal? Why does he think Mae’s bedroom is his? Who is his cruel nemesis?

The tagline for the film is “It runs in the family … he runs from it,” and of course what that means is answered in generally delightful fashion. Despite the harrowing opening, the film is largely about Nolan’s relationship with these versions of his sister, his mother, Klara (Clara Roscoe), and his Uncle Boon (Brian S. Lewis). We quickly learn he’s been hopping through different parallel universes via mirrors. Although the how is obscured until a moment of third-act revelation, the sci-fi concept is simple enough that it works even before the big reveals. Everything leads back to Randall (Matt Shimkus), Nolan’s father, who, in Mae’s universe, was not around for her childhood …

As far as the family comedy goes, the cast is good and embodies its characters well. It’s set in 1999, and Nolan’s uncle in particular is terrified about Y2K. I forgot that was a thing, but it’s a nice touch that feels decidedly retro in 2021. There are a number of 1999 references and sight gags. The alternate universe also makes tongue-in-cheek references to alt-universe holidays. Thanksgiving for Christmas! Little differences between the different worlds are cleverly constructed and keep the story clear, no small feat considering most of the movie takes place within a single house.

When it comes to low-budget, essentially bottle sci-fi, a little ambition goes a long way. Elements like the monster makeup work (done here in a department led by Lauren Young) make or break a film. The baddie here is pretty spectacular, borrowing some elements from classic slashers with new twists.

What ultimately sets Portal Runner apart from the pack, though, is its focus. Despite the one-hour runtime, which does lag a bit in the middle, the film as a whole works because the focus is on the family relationships formed over the course of Nolan’s quest. The cast has chemistry and the script, by Tallis Moore and J.D. Henning, is solid. When the action climax finally arrives, it feels earned and exciting. There are some good, clever beats to top it off. This is a fun, impressive indie science-fiction production arriving just in time for the holiday season — no matter which holiday you’re celebrating.