Plot summary

The film opens with Megamind starting his first day as a hero. He builds himself new devices that provide him with superpowers, and to wipe the slate clean and make a fresh start he sells away all his old evil devices, to customers who can use it for non-evil purposes... except for two, the Death Ray from the film and a button. The Death Ray understandably had no takers (considering it took out Metro City's hero Metro Man in the first place), and when Megamind and Minion press the button, it unleashes Megamind's most evil creation ever: the Mega-Megamind, a giant robot programmed with Megamind's evil personality. The Mega-Megamind takes his creator to be Metro Man, and starts his attack, programmed never to stop until his target is dead!Megamind puts his new power-giving devices to the test, but they prove to be useless against the robot. Megamind and Minion are quickly forced into hiding; Megamind is disappointed at his failure as a hero, but Minion advises him to stop copying Metro Man and tackle the problem as himself. Megamind discovers the Spider-Bot, an invention Minion couldn't bear to sell away, and uses it to draw the Mega-Megamind's attention while Minion activates the Death Ray. Although there's a hurdle when Minion has to look for the remote to activate the ray, he manages to find it in time. The Ray blows up the Mega-Megamind, and Megamind has successfully proven himself as a hero.The film ends with Megamind taking back all his devices, deciding to instead use them heroically. He and Minion see that Metro City has created a distress signal, showing to their great joy that they are now legitimate heroes to call in a crisis. And off they go on a new adventure...