Significant Other

A red, meteor-like object streaks through the night sky and crashes into the Pacific Northwest forest. A deer wanders near the glowing crater and is suddenly snatched by a tentacle. Something has arrived.

Ruth and Harry have been together for six years. Harry loves camping; Ruth has severe anxiety tied to childhood trauma and her parents' toxic marriage, and keeps medication close. Harry has finally convinced her to do a remote backpacking trip. At a scenic overlook above the ocean, Harry proposes. Ruth panics and rejects him, reminding him they had agreed marriage wasn't for them. He's hurt; she's ashamed and afraid.

They continue the trip, both noticing odd things — dead animals, environmental wrongness, the sense of being watched. Ruth wanders off alone and finds a cave connected to the meteor impact. Inside is a strange blue pool. Beside it, in an alien cocoon, is Harry's preserved corpse. The Harry walking around with her is not Harry. The alien at the bottom of that pool can absorb biological matter and replicate it; it killed and copied him.

Back at camp, "Harry" is almost normal, with small slips in speech and behavior. Overwhelmed, Ruth leads him to a cliff edge under the pretense of reconciliation and tries to push him off. He survives. From his perspective it looks like she snapped; from hers, she's trying to kill an impostor.

Ruth wanders dazed through the woods and encounters another couple camping. The alien Harry catches up and kills both of them swiftly, confirming for the audience what Ruth has known since the cave.

The alien has a problem. Replicating Harry meant absorbing his memories and emotional patterns — including his love for Ruth. The entity doesn't understand the feeling and cannot override it. It tries to kill Ruth multiple times and hesitates each time. It begins talking to her as a confused partner as much as a predator, trying to rationalize itself with the love it inherited.

The alien Harry takes her to a secluded beach and reveals his spacecraft. He tells her he is part of an incoming invasion that will soon overrun Earth, and offers her a deal: come with him to another planet as his companion before the invasion arrives. It's not romantic — it's Harry's love refracted through the alien's logic. Ruth pretends to play along, then stabs him in the chest and lures him into the water. A shark, drawn by his blood, attacks him. She uses the chaos to escape.