Struggling to escape her writer's block with the deadline for submitting pages to her publisher fast approaching, Sara (Coleman) and her friend and publisher, Kelly (Shlesinger), visit an art gallery. On their outing, the pair happen upon a handsome, free-spirited art critic (Thune) standing on a bench giving an impassioned plea and Sara is instantly transfixed. When Sara comes across the handsome stranger again, wearing a cowboy outfit and busking, she develops a need to learn more about this mysterious man with many personas. As she learns more about him, the pair's relationship, along with Sara's stagnant creativity, begins to grow.
While her town is being terrorized by a serial killer known as the Blissfield Butcher (Vaughn) armed with an ancient mystical dagger, bullied high school student Millie Kessler (Newton) finds herself alone while waiting for a ride home after the homecoming football game. Dressed as her high school mascot, Millie is stabbed in the shoulder by the killer and, before he can question the identical wound that mysteriously appeared on his own shoulder, the Butcher is scared off by Millie's sister arriving to collect her. The morning following the attack, Millie and the Butcher wake up in each other's bodies. Realizing that he is not nearly as suspicious in Millie's body, the Butcher begins a reign of terror on Blissfield Valley High School while Millie looks for a way to switch back before she is stuck in the body a middle-age psychopath forever.
After a spaceship malfunctions upon re-entering Earth's atmosphere in 1983, the sole survivor, cosmonaut Konstantin (Fyodorov), remains under constant observation in an isolated military facility. When Dr. Tatyana Klimova (Akinshina) is called in to consult on his condition, she is not made aware of the true reason for his quarantine: he has brought back an extraterrestrial life form in his body that feeds on living humans.