Hugh Everett III proposed in the 1950s that every possible outcome of a quantum event actually happens, each branching into its own separate universe, a theory the physics establishment largely ignored during his lifetime. His son Mark Oliver Everett, lead singer of the band EELS, barely knew him growing up and sets out after his father's death to understand both the man and the science. Mark admits his father was more like furniture in the house, a presence hunched over notations at the dining table while remaining a stranger to his own family. The search takes him to NASA's offices and the Bohr Institute in Denmark, where he sits down with physicists who now treat Many Worlds as a serious contender in quantum mechanics, as well as with people who knew Hugh personally. Interviews trace a life marked by brilliance, professional rejection, and what the film frames as undiagnosed depression. The physics and the family story run side by side throughout, with Mark's own grief and curiosity providing the frame for a theory that suggests his father might, in some sense, still be living out every version of his choices.