Past Lives follows the life of disturbed young man Will Stratton. After being released from the hospital with an unrevealed diagnosis, he begins to experience panic attacks, slowly unearthing distant memories of his past. At the same time, Will begins to realize that his life is rapidly changing, and must learn to cope with his newfound issues. As time continues to pass, Will's health gradually deteriorates, causing his panic attacks to become more vivid. This, in turn begins to affect his mood and actions, as noticed by his roommate. Continuously growing more delusional, Will's visions soon become a reality, one that he has not choice but to face.