During a stopover in Germany in the middle of a carefree road trip through Europe, two American girls find themselves alone at night when their car breaks down in the woods. Searching for help they find only an isolated villa, whose mysterious owner, Dr Heiter, takes them in for the night. The next day they awake to find themselves in the basement, trapped in a terrifying makeshift hospital with another one of the doctor's abductees. Dr Heiter explains to the three of them that he is retired surgeon who had specialized in separating Siamese twins. However his three "patients" 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'.