Jax barely recognizes his friend Aiden anymore. Besides no longer partying, Aiden is getting married, moving to the West Coast, and he's started eating healthy food. Jax has invited Aiden to his uncle's cabin for one last sleepover-a kind of bachelor party just for themselves. However, when a strange, slimy creature is discovered, the two guys become hosts to its craving for human bodily fluids. And to encourage them to produce more nourishment, it begins integrating into their physiology and changing them... The slime-creature means no harm. But it also doesn't know the meaning of rest. And when Aiden's soon-to-be wife Savannah shows up, the slimy transformations and messes keep on growing and growing...