On a graduation road trip, Caleb has a nightmare in which he enters the Cave of Lust with the people closest to him, only to be devoured by a monster lurking inside. When he wakes, he discovers the cave is their destination.
His girlfriend Mia lures him inside with the promise that they will finally lose their virginity together. But Caleb has no idea that Mia and his best friend Tyler have been running an OnlyFans account together—and the entire trip is a setup to film his first time, reveal their betrayal, and monetize his breakdown.
When the truth comes out, the group turns on one another, spilling blood inside the cave. Their blood and desire awaken a Siren that can take the form of its victims. What begins as a secret porn shoot becomes a bloodbath, as lust, jealousy, and greed fracture the group and the creature hunts them through the dark. In the Cave of Lust, Caleb can no longer trust what he sees—or who he desires.
