Twin gynecologists, Beverly and Elliot Mantle, operate a successful medical practice in Toronto, specializing in fertility and treating female patients with innovative techniques. Despite their professional success, the brothers share a deeply unsettling personal bond, often pretending to be each other to exploit romantic relationships with their patients. When famous actress Claire Niveau visits their clinic, her unique anatomy intrigues them both, and they begin covertly sharing her as a lover without her knowledge. However, as Beverly becomes emotionally attached to Claire, he struggles with feelings of guilt and jealousy, leading to a deterioration in his mental state.

Beverly's descent into paranoia and drug abuse causes friction between the twins, further complicated by Claire's eventual awareness of the deception. As Beverly grapples with his unraveling psychological state, his once-clear boundary between professional duties and personal obsessions begins to blur. The twins' symbiotic relationship faces unprecedented strain, pushing their identities and ethics to the brink. The deeper Beverly falls into madness, the more Elliot must navigate the delicate balance required to maintain their shared life and practice, challenging their lifelong dependence on each other.