On her first day at the Mount Royal Psychiatric Institute, Suzanne meets her team, including Mortimer, an intriguing intervention officer who must accompany her at all times. The arrival of a new patient puts the team to the test.

While carpooling, Suzanne and Mortimer encounter Mr. Dallaire, a patient from Wing D, on the streets of Montreal, and discover that he is in the midst of a crisis. Meanwhile, a newcomer with a mysterious past enters the Institute.