Plot

Diane's feelings for Jack -- the girl she met over the summer -- begin to manifest themselves in terrifying ways when she learns that her friend will soon be moving away.

Jack and Diane, two teenage girls, meet in New York City and spend the night kissing ferociously. Diane's charming innocence quickly begins to open Jack's tough skinned heart. But, when Jack discovers that Diane is leaving the country in a week she tries to push her away. Diane must struggle to keep their love alive while hiding the secret that her newly awakened sexual desire is giving her werewolf-like visions.—filmsalt.com

Diane is a young, blond British teenage girl who experiences chronic nosebleeds. She checks herself in a mirror and she is transformed into a monster before falling unconscious.

Earlier...

Diane walks in the streets of New York trying to borrow cellphone in order to call her twin sister Karen to ask for a ride home. As to no avail, she enters a clothing store and asks to use a phone. There, she meets a dark-haired lesbian of her age, Jack, who is clearly smitten by Diane. Diane's nose starts bleeding again and Jack gives her a hand.

Jack then takes Diane to a night club. When they get there, Diane seems nauseous and a lot of blood is shed more from her nose and she goes to the restroom. This scene is parallel to as the beginning of the film. She gains unconsciousness and meets up with Jack and the girls ferociously kiss each other on a couch in the nightclub lounge.

The next morning, the girls part ways and Jack is uncritically hit by a car. Back at Diane's apartment, she is reprimanded by her stern aunt Linda and tells her she is grounded. Diane strikes back by telling her she's not her mother. Both of the girl feels misunderstood back in their homes. Jack comes home from the hospital and spats with her neglectful mother. Nevertheless, Diane visits Jack in her home. Jack confides with Diane about her sentimental cassette tape from her late brother. Another day later, Jack visits Diane in her home where the girls get into an argument when Linda intentionally tells Jack about Diane leaving for school in France.

After Jack leaves her, Diane suffers from desolation and she starts to unravel. Meanwhile, Jack hangs out with a lesbian, Tara, whom she works with. They have an intimate moment but Jack rebuffs her shortly after. The next day, Diane hangs out with one of Jack's friends, named Chris, and Jack is startled. The girls play a game as to whoever wins would either leave or stay. Jack wins and Diane is forced to go home. Jack gets back to Chris where he finds a video of Diane's sister Karen getting raped in an adult website. Feeling sorry for her sister, Jack finally reconciles with Diane in her home.

Over the next few days, the girls finally spend much time romantically with one another. One night, Jack has a dream of Diane transforming into a monster and devouring her heart. She wakes up only to find Diane on her side with blood gushing out of her nose. As days are narrowed down before Diane would leave for school, the bond between the two girls starts to turn debilitated.

One day, the girls go to a hotel swimming pool to swim and while in the locker room, and the lights suddenly go off. Afraid of the dark, Jack seeks help from Diane whom she had given a polaroid camera before the lights went off. The couple are separated and Diane searches for Jack by flashing through her camera. She encounters the same monster from earlier, and she is found sobbing by Jack. The two girls console each other, finally letting go of their fears. Jack goes to see Diane on her last day before she departs for school and the girl's relationship is compromised.

A few weeks later in Paris, France, Diane receives a gift from Jack and reveals it to be the cassette tape. She turns the song on and listens to it profoundly, reminiscing about her encounter with Jack.