When California girl Susan Murphy (REESE WITHERSPOON) is unwittingly clobbered by a meteor full of outer space gunk on her wedding day, she mysteriously grows to 49-feet-11-inches tall. The military jumps into action and Susan is captured and put into a secret government compound. There, she is renamed Ginormica and held along with a ragtag group of Monsters: the brilliant but insect-headed Dr. Cockroach, Ph.D. (HUGH LAURIE); the macho half-ape, half-fish, The Missing Link (WILL ARNETT); the gelatinous and indestructible B.O.B. (SETH ROGEN); and the 350-foot grub called Insectosaurus. Their confinement is cut short, however, when a mysterious alien robot lands on Earth and begins storming the country. In a moment of desperation, The President (STEPHEN COLBERT) is persuaded to enlist the motley crew of Monsters to combat the alien robot and save the world from imminent destruction.