In 1959 an alien experiment containing vile, sluglike organisms that possess their hosts crashes to Earth, where one of the slugs takes over a young Lover’s Lane habitué; flash-forward to 1986, when hapless nerds Jason Lively (brother of Gossip Girl’s Blake Lively) and Steve Marshall discover the corpse, cryogenically frozen in their college lab, and accidentally free it as part of a prank. The body unleashes its extraterrestrial passenger, which proceeds to infect the student population at a breakneck pace.