Set in a different northwestern city a few years after the events of the first film, the story opens on a snowy night with a striking moment: Delia, a beautiful young woman, shares a kiss with a guy inside a car. The moment is briefly interrupted by a passing officer, but once they resume, something else emerges—tentacles that erupt from her chest, signaling danger and a haunting return of the phenomena from the previous chapter.
In a college Evolutionary Biology class led by Prof. Erwin Buckton, the narrative threads begin to braid together. The instructor revisits the first film’s central survivor, Luke Callahan, who is shown to have endured what he once faced. The class also includes Sam Compton and Stephanie Baxter, who observe the uneasy overlap between science and the uncanny. After the lecture, Luke spots one of the aliens—the enigmatic Constance Snowden—who now masquerades as a doctor. His paranoia intensifies as he visits Dr. Alana Geisner, a psychiatrist, where he confesses that the aliens and the earlier events might be more than dreams, even as he awakes days later in a hospital under her care. Geisner supplies him with a full container of Anti-Hallucigens, a detail that only seems to heighten his agitation and sense of unease.
Back in the dorms, Sam and his roommates—Henry Robbins, Peter Brunson, and Nick Dean—cook up a reckless, if secret, summer plan: a “sex-fuel” competition to see who can hook up with the most partners by summer’s end, with the whole pursuit recorded as proof of victory. Although Sam initially resists, the promise of cash and the thrill of the scheme draw him in, weaving a volatile dynamic among friends and rivals alike. Throughout this subplot, the shadow of Constance Snowden’s influence lingers, curiously guiding the group’s perception of danger and desire.
A second alien presence, Jasmine, also cloaked in human beauty, is pulled over by the same officer who interrupted the opening scene. Jasmine seduces him, but the encounter ends in tragedy as he is killed. Meanwhile, Luke’s suspicion about Constance intensifies when he encounters her again—this time while she watches and manipulates events from the periphery. Constance has become the leader of the Decoys, a faction using telepathy to probe and exploit the most intimate fetishes and desires of their intended mates. As she expands her reach, Constance warns her fellow Decoys—Jasmine and Delia—not to leave corpses for the police to discover, signaling a chilling strategy to remain hidden while drawing on Luke’s growing awareness of their survival.
Luke’s growing knowledge about the Decoys deepens when he learns that Constance has deduced a key tactic: to incite passion and arousal in their mates, and to avoid leaving behind evidence that could expose them. He and Sam become determined to uncover who among their peers might be a Decoy. The tension escalates when Buckton’s office becomes a scene of misdirection as Constance falsely positions Luke as paranoid and delusional, though Buckton’s later observations—drawn from Luke’s precise drawings of the Decoys, including one figure bearing a striking resemblance to Constance—suggest a more troubling truth.
Seeking a lead, the group heads to a bar near campus to kick off the competition, where only Nick proves successful in his pursuit. Henry, meanwhile, connects with Delia, learning of his own fetish for leopard-skin attire, though his virgin status complicates their relationship. An old friend of Sam, Arnold Steiner, learns of the contest and begs to join, injecting a new dynamic into the plan. Arnold’s enthusiasm proves infectious, but an unintended leak of information to other male students risks exposing the scheme. Jasmine seduces Arnold, borrowing Sam’s phone to extend the encounter, only to crash into a dangerous moment when Jasmine’s true nature—tentacle-assisted intimacy—surfaces. Arnold is found paralyzed, his phone frozen, and when Sam retrieves him, the police dismiss the incident as a prank, leaving Arnold’s body missing from the scene.
Stephanie warns Sam that Luke’s account of the aliens might be tied to a broader pattern, and she drops a chilling note that they are “allergic to fire.” Peter encounters Delia again, who dresses as a schoolgirl; his attempt to engage is thwarted by a malfunctioning heating system. Peter relays what happened to Sam and Henry, describing Delia’s supposed weakness, while Stephanie and Luke become fixated on the idea that these alien presences manipulate human desire by exploiting fear and heat. They break into Luke’s dorm room to study a trail of newspaper clippings about aliens and the fate of frozen bodies, with Stephanie remarking that the air in the room is stifling and oppressive.
Dr. Geisner remains a steady, if initially cautious, presence in Luke’s life. She insists she is not a Decoy, and her reassurance convinces Luke to trust her again. Outside, Sam confirms his belief in Luke, and the two begin to track Constance more directly. Luke spots Constance again but is blocked by Sam and a hospital guard, and Geisner intervenes to get Luke released from custody. The duo then pursues a lead to a hospital-leaning, hidden lair: the morgue, where the Decoys have established a nest thanks to its cold environment and infrequent use. Armed with flares, improvised Molotov cocktails, and flamethrowers cobbled from a lighter taped to hairspray, they confront the threat in earnest.
In a brutal turn, the hospital becomes a battleground. Henry kills Delia, while Peter and Nick kill Angeline. Sam and Stephanie manage to kill Jasmine, acting out of loyalty to Arnold and a need to thwart the Decoys’ reach. Dr. Geisner arrives in time to witness the last confrontation with Constance, who reveals her true form, and together with Luke, they manage to kill her. The victory is bittersweet, as Sam and Stephanie end up together, with Sam declared the winner not simply for hooking up the most but for finally finding a real relationship amid chaos.
As they piece together what remains, the group discovers that Buckton and Arnold are not dead after all—they lie cold and unconscious, but alive, in a hidden room. Alien offspring begin to emerge from their fathers’ chests, signaling that the threat is not quite finished. The camera lingers on the aftermath as the chilling final line appears on the screen: The End... Maybe.
