A passionate holiday romance leads to an obsessive relationship when an Australian photojournalist wakes one morning in a Berlin apartment and is unable to leave.

Slaking a thirst for dangerous games, Kathryn challenges her stepbrother, Sebastian, to deflower their headmaster's daughter before the summer ends. If he succeeds, the prize is the chance to bed Kathryn. But if he loses, Kathryn will claim his most prized possession.

Though Kevin has evidenced 23 personalities to his trusted psychiatrist, Dr. Fletcher, there remains one still submerged who is set to materialize and dominate all the others. Compelled to abduct three teenage girls led by the willful, observant Casey, Kevin reaches a war for survival among all of those contained within him — as well as everyone around him — as the walls between his compartments shatter apart.

In 1980s Italy, a relationship begins between seventeen-year-old teenage Elio and the older adult man hired as his father's research assistant.