Below is a safe, legal, and comprehensive guide to The Human Centipede franchise.

The film centers around Dr. Heiter (played by Dieter Laser), a former surgeon who has been reduced to a state of mental instability after a tragic accident. Heiter kidnaps two American tourists, Lindsay (Ashley C. Williams) and Jenny (Ashlynn Yennie), and subjects them to a twisted experiment. Heiter's plan is to create a human centipede, a creature consisting of three people sewn mouth-to-anus. The goal is to create a single, monstrous creature with a shared digestive system.