Alex, a restless teenager, heads to Edwards Island for a weekend party on the last ferry of the season. She isn’t making the trip alone: she’s joined by Ren, her laid-back stoner friend, and Jonas, her new stepbrother. On the island, they meet Clarissa, the ex-girlfriend of Alex’s late brother Michael, and Nona, Clarissa’s best friend who’s also Ren’s love interest. Ren explains the island’s history as a former military base and mentions Maggie Adler, the island’s lone permanent resident who has just died. After camping on the beach, the trio ventures into the network of nearby caves, where rumors say radio frequencies can spark strange, otherworldly happenings.
In a small cavern, Alex twists the radio toward a floating shape and unexpectedly activates a dimensional rift. A voice answers, and the teens begin to experience vivid visions before collapsing. When they come to, Alex and Jonas find themselves in front of a communications tower somewhere else on the island, while Ren, who had been calling from the woods, has also collapsed, and Clarissa reaches them from a decommissioned military fort on the island. The group soon discovers that the woods are full of inexplicable phenomena: Alex’s own reflection speaks to her from the water, objects move on their own, and time begins to loop. The loops are reset when Alex plays a reel-to-reel tape, hinting that memory and rhythm may anchor their reality.
They encounter Nona again, who asserts she has seen an alternate version of Jonas and Alex during one of the loops. The search for Ren continues, and they eventually find him—though not for long, as another loop reveals him possessed by a spectral “ghost.” Using the radio, Alex manages to open another rift, which returns Ren to normal and allows the group to retreat to the tower to regroup. The haunting intensifies when they reach the military fort: Alex’s reflection inexplicably appears in a mirror and begins offering guidance, while a ghost questions their purpose and briefly possesses Jonas, revealing that the ghosts are the crew of a submarine, the USS Kanaloa, presumed lost at sea. Yet the threat remains, and a further rift is used to revive Jonas, who survives the encounter.
The search for Clarissa leads them to a disturbing turn: after a time loop, Clarissa leaps from a ledge, vanishing again as the loop resets. The four friends return to Harden Tower but realize that they cannot simply broadcast a signal off the island. Ren proposes a desperate plan: locate Maggie Adler’s estate and use a boat there to try once more to pierce the veil. At Adler’s home, a possessed Clarissa speaks with Alex, and scattered letters left behind by Adler hint at a deeper history. Adler and her confidant Anna had attempted to communicate with the Kanaloa crew via radio, but Anna was dragged into the rift. The letters reveal a revelation: the Kanaloa crew were not killed by enemy fire but were pulled into another dimension because of the sub’s experimental nuclear reactor. Adler’s messages also imply that the crew intends to seize the bodies of Alex and her friends to slip back into their world from the other side, prolonging their stay on the island long enough for a successful possession.
With that knowledge, Alex and the group uncover Adler’s plan to repair the rifts by crossing to the other side and tuning the radio from within. The story then loops back into time as Alex repeatedly returns to moments she shared with Michael, searching for a way to fix what has happened. In a tense moment, a ghost possesses Jonas and offers a bargain: spare Alex and the others if they leave Clarissa behind. The path forward becomes a choice of impossible weights. Back in the caves, Alex tunes the radio toward a rift that drives her into a void, where she encounters the possessed Clarissa and hears dire warnings from the ghosts: if Alex closes the rift, Clarissa will die or be held by the ghosts. If she leaves through the rift, Clarissa disappears. If she has collected certain letters from Maggie Adler that name the crew members, she may directly appeal to them and secure Clarissa’s freedom. The twist reveals that the reflection guiding Alex is her future self, and a memory-rich conversation with Michael surfaces, in which he confides he and Clarissa plan to leave town and asks for Alex’s counsel. Then time corrects itself.
When Alex awakens again, she finds herself back with Ren, Jonas, Nona, and Clarissa on the ferry home. Jonas confirms that whatever Alex did has mended the rift for now and that the world seems temporarily normal again. The friends realize they have glimpsed versions of their memories and truths during those intervals, and they vow to keep what happened to themselves. Before parting, Nona suggests one final group photo, a quiet, shared moment that seals their pact to carry the secret of Edwards Island’s strange, otherworldly week. The voyage back is calm but underscored by an unspoken reckoning: some conversations, some memories, and some doorways should remain between the people who lived them.
