Laura is 25 years old. She's a journalist, she's single and lives in a small apartment in Mexico City. After a series of short-lived affairs, Laura meets Arturo. After the first time they make love, she is left deeply unsettled. They embark on an intense and passionate sexual relationship, in which pleasure, pain and love merge. As days go by which Laura conscientiously crosses out in a calendar, her secret past resurfaces, pushing Arturo to the limit.