Craig Schwartz is a struggling puppeteer stuck in a passionless marriage with his pet-obsessed wife, Lotte. Desperate for employment, Craig takes a mundane filing job at a peculiar office located on the 7½ floor of a New York City building. One day, he stumbles upon a mysterious, hidden door behind a filing cabinet which, to his astonishment, transports him directly into the mind of renowned actor John Malkovich. Enamored by the thrilling experience of living as someone else, he shares the discovery with his icy coworker, Maxine, with whom he quickly becomes infatuated.

Craig and Maxine capitalize on the portal by charging others for the chance to be Malkovich for 15-minute intervals. The lucrative venture spirals as Lotte also becomes obsessed with the experience, leading to a complex love triangle involving her, Craig, and Maxine. As their exploitations of Malkovich's mind intensify, the trappings of their own identities and the boundaries of human consciousness are put to the test, forever altering their perceptions of self and reality.