"Once the number one surgeon dedicated to splitting up conjoined twins, the mad doctor now has a different agenda – he wants to create an all-new animal by sewing people together, ass to mouth, in a row, and severing the tendons of their kneecaps so they must remain on all fours. After the death of his beloved “3-Dog” (three dogs sewn together into one animal), Heiter decides it is now time to move on to humans. His unfortunate subjects come in the form of two young travelers, Lindsay (Ashley C. Williams) and Jenny (Ashlynn Yennie), who suffer the best of horror plot devices – a flat tire – close to his home on their way to a nightclub."

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http://www.imdb.com/title/tt1467304/