Ana is an integral part of a hotel staff alongside her friends: Dimitri, a DJ, and Max, the cook. Their dynamic shifts when they notice Marsha, a bride on the brink of her wedding, grappling with cold feet. As Ana faces the brutality of their cruel head waiter, an unexpected storm plunges the hotel into darkness, leading Ana to discover a mysterious voice calling out "mayday" in a modified NATO phonetic alphabet. Intrigued, she crawls into an oven, only to find herself falling into the ocean.
Upon surfacing on an unknown shore, Ana encounters Marsha, who now radiates confidence. To her shock, Ana realizes she has lost all her memories. A man dressed as a World War II aviator washes ashore, claiming his plane has crashed nearby amidst a war. Tragically, as the girls depart the beach, the pilot is shot dead. In a surprising twist, Marsha brings Ana to a beached submarine where she resides with two other girls, Gert and Bea. Here, Marsha reveals that this land serves as a utopia, offering refuge from male violence and predation.
Marsha explains that numerous camps of women are valiantly combating the men trying to dominate the island. Eager to learn, Ana shows remarkable adeptness as the girls teach her how to use a rifle. However, when the trio swims, Ana's fear prevents her from leaping from a cliff. An encounter with the head waiter, now dressed as a soldier, escalates into an attack, but Ana manages to escape.
Under the stars, Marsha introduces Ana to her telescope, offering vistas of distant galaxies. Compelled by their mission, the girls begin to send out false distress signals, luring men to their demise amid the storm-infested surroundings. Yet, when a group of men successfully reaches the island, Ana's moral compass falters, leading to tension with the increasingly bloodthirsty Marsha.
Haunted by dreams of driving through a tunnel, Ana encounters a distress signal one night from a man stranded near the shore. He reveals he is trapped in a submarine due to electrical failures and promises to return for her. When Marsha intercepts the truth, she despairs at Ana's lies. The tension escalates when Bea is captured by men, prompting a rescue mission. In a climactic moment, Ana is forced to confront her fears and ultimately saves Bea by taking out their captors.
As internal conflicts brew within their group, Gert questions Marsha’s motives, citing the peril of risking Bea's safety. Ana gradually transforms, and during a patrol, she finds an older man peeling potatoes—Max—who expresses a desire to escape the war. This simple connection prompts Ana to reflect on her own longing for peace.
As Ana’s dreams intensify, she once more sees the light at the end of the tunnel. Following an altercation with Marsha, Ana confides in Gert about her plans to leave the island. However, Gert casts doubt on her decision, warning that her absence could spell doom for everyone on the island. Nonetheless, Ana is determined, buoyed by encouragement from Gert.
Driven by newfound resolve, Ana learns of the girl camps' solidarity and devises a plan to navigate the storm back to where she began. Uneasily, she realizes that Marsha has eavesdropped on their conspiratorial discussions. Marsha confronts Ana, unable to comprehend why she would forsake everything she has built. Ana, resolved to embrace the darkness to discover her own light, battles with her own conscience and the reality of what Marsha has encouraged her to become.
As tension builds, Gert, Bea, and June assist Ana in charting her course. As the moment of departure approaches, a profound bond develops between Ana and Bea, who deeply desire to remain connected despite the impending separation. With the storm brewing behind her, Ana bravely jumps into the tempestuous sea, currently fighting both nature and her own history. Caught in a rip tide, she succumbs to unconsciousness, only to hear Marsha's voice ringing out, echoing a message from her dreams.
In a mesmerizing climax, Ana is transported back to the hotel, regaining clarity of her past. She strides confidently into the banquet hall where Dimitri is playing music, drawing upon her venture to culminate the experience as she takes the microphone, poised to sing.
