Alex, a teenager, is on the last ferry heading to Edwards Island for a weekend party. She is accompanied by Ren, her stoner friend, and Jonas, her new stepbrother. On the island, Alex and company meet Clarissa, the ex-girlfriend of Alex's deceased brother Michael, and Nona, Clarissa's best friend and Ren's love interest. Ren explains the island was once a military base and that the island's only permanent resident, Maggie Adler, has recently died. After camping on the beach, Alex, Ren, and Jonas explore the nearby caves, where it is rumored certain radio frequencies cause supernatural events. In a small cavern, Alex tunes her radio to a floating shape and unexpectedly forms a dimensional rift. A voice answers and the teens experience visions before passing out. Jonas and Alex awake in front of a communications tower elsewhere on the island. Ren calls, having passed out in the woods, while Clarissa calls from the decommissioned military fort on the island.
