Kim and Ron start a new school year, only to learn that Ron's family is moving to Norway. This puts a strain on their partnership, just as Dr. Drakken, Monkey Fist, and Duff Killigan team up to find and use an ancient time travel device to rule the world. Attacking Kim in the past, present, and future, can these villians succeed? Or will an unforeseen force be more destructive?
After Dexter is confronted with robots who wish to "destroy the one who saved the future," he uses his time machine to see how he saved it. They declare that they are here to destroy the one who saved the future, and make ready to attack Dexter. Dexter easily destroys them with the use of various tools and gadgets from his lab. However, news that he is "The One Who Saved the Future" intrigues him, and he decides to travel through time to discover how cool he is. In the first time period he visits, Dexter finds a tall, skinny, weak version of himself working in office-designing cubicles, with Mandark as his rich, successful boss. The child Dexter unwittingly reveals the existence of blueprints regarding the "Neurotomic Protocore", and Mandark steals it after the two Dexters move forward in time.
Inventor Flint Lockwood creates a machine that makes clouds rain food, enabling the down-and-out citizens of Chewandswallow to feed themselves. But when the falling food reaches gargantuan proportions, Flint must scramble to avert disaster. Can he regain control of the machine and put an end to the wild weather before the town is destroyed?
A quirky, dysfunctional family's road trip is upended when they find themselves in the middle of the robot apocalypse and suddenly become humanity's unlikeliest last hope.