Out beyond the far reaches of space, an unknown planet explodes sending a strange meteorite across the galaxy, heading towards Earth. Meanwhile, Susan Murphy of Modesto, California is going to be married to news weatherman Derek Dietl. Just before the ceremony, she is hit by the meteorite and its energy causes her to glow green and grow to enormous size with her hair turned white. She is tranquilized by the military and awakens in a top secret Area 51 that houses monsters of which the public are ignorant. She meets General W.R. Monger, the U.S. Army officer in charge of the facility, and her fellow monster inmates: Dr. Cockroach PhD, a mad scientist who became half-human, half-cockroach after an experiment; B.O.B. (Benzoate Ostylezene Bicarbonate), a brainless, living mass of blue goo as a result of a food flavoring mutation; Insectosaurus, a massive mutated bug standing 350 feet in height, and the Missing Link, a prehistoric 20,000 year old fish-ape hybrid who was thawed from deep ice by scientists. Susan herself has been renamed to Ginormica.