Triangle

Jess prepares to take her autistic son Tommy on a boat trip with her friend Greg. Tommy becomes upset, and she tells him that he just had a bad dream. This sets the tone for the day and the tension between care and escape.

Jess heads to Florida harbor without Tommy, explaining that he is at school. She boards Greg's boat with Victor, Sally, Downey, and Heather. The mood is tense beneath a calm surface.

On the boat, Jess dreams of crabs on a beach and wakes disturbed. She quickly forgets what disturbed her, leaving the moment unresolved. The dream hints at a deeper unease that will unfold.

A storm approaches as they sail. Greg radios the Coast Guard while a distress signal from a woman claims someone is killing everyone but is cut off before the location is given. The air thickens with danger.

The sudden storm capsizes the boat. Heather is swept away by the waves, and the remaining five survivors manage to climb onto the overturned sailboat as the weather clears. The group is left adrift with the loss of their companion.

A passing ocean liner, the Aeolus, rescues the five survivors. The ship itself seems deserted when they board, and they begin to explore with a mix of relief and unease.

Jess experiences a sense of deja vu while exploring the ship. They find her keys and fresh food in the dining room, and someone watches them. Greg dismisses a blood stained hint about going to the theater as a prank.

Victor, with a head wound, tries to strangle Jess; she fights him and he collapses. Later they reach the ship's theater where Greg lies dead from a gunshot, and Sally and Downey claim that Jess shot him.

A burlap masked shooter shoots Sally and Downey. Jess runs, grabs an ax, and disarms the shooter. The attacker tells her that she must kill them to get home before being knocked overboard.

Jess hears yelling and sees another copy of her group on Greg's boat; a new set boards the ship and spots her after she drops her keys. She tries to warn the new Victor, who chases her and she injures his head on a wall hook.

She finds dozens of her own lockets and notes in her handwriting telling her to kill them all. She takes a shotgun and confronts the new group, intending to change the pattern. A third Jess shoots the new Greg and stabs the new Downey and Sally.

The old Jess chases the new Sally, who triggers the distress signal heard earlier. Dozens of Sally corpses appear on a deck, and the new Jess kills the old Jess. The overturned boat returns again with another copy, signaling the loop restarting after everyone is killed.

Desperate to stop the cycle, Jess writes in blood on the mirror, dumps bodies overboard, and instructs the latest Sally and Downey to go to the theater. She dons the shooter's outfit and burlap mask, shoots the latest group, and is then knocked overboard after urging the latest Jess to kill everyone.

She awakens near crabs on a beach, realizing she is earlier that same morning. She returns home and yells at Tommy, then kills her other self and tells Tommy that he just had a bad dream. She places the bagged body in her car trunk and leaves with Tommy.

A seagull dies on the windshield and she notices a pile of dead seagulls, signaling the loop persists. She tries to drive toward the harbor with Tommy, but crashes into a truck, killing Tommy. A taxi driver offers a ride to the harbor, and she promises to return. Exhausted, she ends up back on Greg's boat, starting the loop again.