A woman transformed into a giant after she is struck by a meteorite on her wedding day becomes part of a team of monsters sent in by the U.S. government to defeat an alien mastermind trying to take over Earth. When a meteorite from outer space hits a young California woman named Susan Murphy and turns her into a giant monster, she is taken to a secret government compound where she meets a ragtag group of monsters also rounded up over the years. As a last resort, under the guidance of General W.R. Monger, on a desperate order from The President, the motley crew of Monsters is called into action to combat the aliens and save the world from imminent destruction!

A sausage strives to discover the truth about his existence. The products at Shopwell's Grocery Store are made to believe a code that helps them live happy lives until it's time for them to leave the comfort of the supermarket and head for the great beyond. However, after a botched trip to the great beyond leaves one sausage named Frank and his companion Bun stranded, Frank goes to great lengths (pun intended) to return to his package and make another trip to the great beyond. But as Frank's journey takes him from one end of the supermarket to the other, Frank's quest to discover the truth about his existence as a sausage turns incredibly dark. Can he expose the truth to the rest of the supermarket and get his fellow products to rebel against their human masters?