In Philadelphia in 1961, Elijah Price is born with osteogenesis imperfecta#Type I osteogenesis imperfecta, a rare disease that renders sufferers' bones extremely fragile and prone to fracture. Elijah—who grows up to become a comic-book art dealer—develops a theory, based on the comics he has read during his many hospital stays, that if he represents extreme human frailty, there must be someone "unbreakable" at the opposite extreme.