To any outsider, it would appear that Iris (Sophie Thatcher) and Josh (Jack Quaid) have a relationship built on mutual adoration. Their meet-cute story establishes that it was love at first sight, and their interactions in the lead-up to a weekend getaway with his friends show a lot of kindness and caring between them. Iris is sweetly nervous, concerned that Josh’s friends don’t like her. Josh is gently supportive, offering her assurances that all will go well. “Just smile and act happy” is his advice. The truth of the matter is, of course, more complicated.

Written and directed by Drew Hancock, Companion is a horror film at its core, moving to familiar beats of set-up, shock, and bloody mayhem. It’s also a scalding comic fable about living as a women in modern society, where codependent subservience is the default expectation of even the kindest romantic partners and there are unseen manipulations designed to ruthlessly strip away agency. Even the authorities are no help, as they’re instinctively inclined to return a desperate woman in need right back to the horrible domestic situation she’s trying ever so hard to escape.

At least some of the promotional efforts around Companion spoil a major plot detail of the film, and, to be fair, the reveal comes not far in at all, which is a requirement for most of the storytelling to make sense. I’m refraining from typing anything about it, though, because the first chunk of the movie so artfully hints at it while holding the defining detail back. It’s a reflection of the overall strength of Hancock’s screenplay, which is relentlessly clever in exploring possibilities with the conceit for both poignancy and effective gags. Given a role with a daunting degree of difficulty, Thatcher is a worker of wonders. She stays within the built-in confines of character while signaling the insight and growth that comes with the sort of challenging revelations that entirely upend her sense of self.

Companion falters a bit in its final act. Like many of its kindred features, the film indulges in too many fake-out near-endings as a means to prolong the suspense. Given the way Iris had been developed to that point, she deserved a cleaner, more decisive ending. It’s to Hancock’s credit that this creative choice is more of a glitch than a fatal error. Through his inspired efforts, the movie is largely good company.