Watch It Now > Watch Triangle
Jess (Melissa George) lives with her autistic son, Tommy (Joshua McIvor). She sets her daily routine, when suddenly there is a ring at the door. Jess opens the door to find no one. Then, Jess packs up for a trip on a boat with friends. Sometime afterward, Jess goes down to the nearby harbor, greeting friend Greg (Michael Dorman). Accompanying him are Victor (Liam Hemsworth), Heather (Emma Lung), and the couple Downey (Henry Nixon) and Sally (Rachael Carpani). Greg had also invited Jess to bring her son Tommy with her, but when he asks Jess where he is, she claims he's at school.
The boat goes out to open waters when the wind suddenly dies down. Also of question is a strange electrical storm that is steadily approaching. Greg tries to radio the coast guard, but finds their communications wavering. Another radio communication comes in, but Greg's request for coordinates of this unknown communication soon gives way to more static. The storm soon reaches the boat, which capsizes, but not before Heather is swept out of the boat into the waters. When the weather clears, the survivors climb onto the upturned boat, unsure what to do next. Suddenly, a large cruise ship floats into view, and the survivors quickly board it, only to find no one on deck or in the halls. As they trek through the corridors of the ship, Jess begins to have an eerie sense of déjà vu. As they keep moving around the ship, a sudden noise catches their attention. What they find are a set of car keys that are exactly like the set that Jess carries. No one is sure what this can mean, and the search continues.
Jess splits up, only to then encounter Victor who is bleeding, and attempts to strangle her. Jess manages to escape, only to hear a gunshot. Finding herself in the theater of the ship, she finds Greg shot, with Sally and Downey accusing her of killing him. Suddenly, more gunshots ring out, with Sally and Downey being killed. Jess gives chase and soon encounters a masked figure with the shot gun. Finally confronting the figure, it speaks in a muffled speech through the mask, and Present-Jess pitches her over the side into the ocean below.
Confused and upset, with everyone around her dead and having no idea who the masked figure was, Jess goes to a cabin on the ship, only to hear yelling from off the boat a few moments later. Looking over the edge, she is shocked to see the overturned boat, and everyone (even herself) calling to be rescued. Jess soon realizes that she is trapped in a time-loop that apparently repeats itself when everyone on the ship is killed. She sets to change the loop, however, the masked figure, revealed to be another Jess, savagely kills the group, but is thrown overboard by a third version of Jess. Witnessing this is a present-counterpart Jess.
Mentally fearful that she may never see her son again, Jess attempts to follow the events of what happened and kill everyone. She soon dons the mask and other clothing that she had seen previously, until in a confrontation with herself, she ends up falling off the ship, just like in the original loop. Jess soon after awakes on a beach and makes it back home, only to find herself there that morning, where the film started. However, this time, it is revealed in Jess's daily routine that she was abusive with Tommy. Present-Jess sneaks into the house, and using a hammer, bashes her past-self to death. Unfortunately, Tommy witnesses this, and Present-Jess assures her son he just had a 'bad dream.'
Jess then puts the dead body in a black duffle bag, before putting it in her car's trunk. Jess then proceeds to drive her and her son to the pier for the sailing trip promising that things are going to be different from now on. As they drive along the ocean, a seagull suddenly slams into the windshield, leaving bloody streaks. Jess pulls over to retrieve the dead bird and throw it into the ocean. However, when she goes to throw it over the edge of the embankment, there are multiple dead seagulls pooled in the area where she was planning to dispose of the one she just hit.
Jess disposes of the bird quickly, and then rushes to get into her car. As they take off, Tommy begins to panic over the blood on the windshield. As Jess turns to calm her son, she turns into the incoming traffic lane, and ends up hitting a truck. In the aftermath, we see Jess watching her body and that of her son's lying on the highway. A man in a nearby taxi is observing this as well, saying that there's nothing that anyone can do now. Jess then requests the driver take her to the harbor, where she starts her trip on the boat again, hoping to reverse her son's death.