Haskell (Michael Caine) is assigned a job by his boss, the aristocratic Landon-Higgins (James Fox), to highjack a high security van in broad daylight while it's in the shadow run (out of radio contact with the main security firm). He assembles a team to carry out the heist, but things don't go according to plan and Haskell begins to think his boss might be double crossing him. Add to this, a teenage boarding school pupil has already witnessed some of the meetings of the team and Haskell's in real trouble.
Having just returned from a mission to Mars, Commander Ross isn't exactly himself. He's slowly becoming a terrifying alien entity with one goal -- to procreate with human women! When countless women suffer gruesome deaths after bearing half-alien offspring, scientist Laura Baker and hired assassin Press Lennox use Eve, a more tempered alien clone, to find Ross and his brood.
When Quinn, a grouchy pilot living the good life in the South Pacific, agrees to transfer a savvy fashion editor, Robin, to Tahiti, he ends up stranded on a deserted island with her after their plane crashes.
When guardian angel Seth -- who invisibly watches over the citizens of Los Angeles -- becomes captivated by Maggie, a strong-willed heart surgeon, he ponders trading in his pure, otherworldly existence for a mortal life with his beloved.
When some very creepy things start happening around school, the kids at Herrington High make a chilling discovery that confirms their worst suspicions: their teachers really are from another planet! As mind-controlling parasites rapidly begin spreading from the faculty to the students' bodies, it's ultimately up to the few who are left – an unlikely collection of loners, leaders, nerds and jocks – to save the world from alien domination.
Having never fully recovered from a prom date that became a total disaster, a man finally gets a chance to reunite with his old prom date, only to run up against other suitors including the sleazy detective he hired to find her.