In this sequel the director Tom Six kind of goes meta, since we see Martin, the protagonist, going mad after watching “The Human Centipede: First Sequence” and then starts kidnapping and bludgeoning his own victims in order to emulate the previous sequel. Creepy.
Namely, Martin decides to make his own human centipede with twice the bodies, but without any skills necessary for the job. He cuts and staples his victims until they are forged to each other by way of the digestive tract. Long story short, some lips get stapled to where the Sun don’t shine.