Two American girls find themselves trapped in a terrifying makeshift hospital by a retired surgeon,Dr. Heiter. The doctor explains that he is retired surgeon who had specialized in separating Siamese twins. However the girls are not about to be separated, but joined together in a horrific operation. He plans to be the first to connect people, one to the next, via their gastric system, and in doing so bring to life his sick lifetime fantasy: the human centipede.