Megamind is shown falling at the beginning of the film and he explains how. Many years ago, Megamind was a super-intelligent alien who was evacuated from his homeworld as a baby, as was Metro Man; the two later arrive on Earth, falling into the paths of super villainy and superheroism respectively and grow up as rivals fighting to take control over Metro City. Megamind is consistently defeated by Metro Man and is in prison. After using a holographic watch to escape with the aid of Minion, a talking fish with the robotic body of a gorilla, he kidnaps Metro Man’s supposed love interest, reporter Roxanne Ritchi and holds her hostage to lure him into a trap. Finding that copper is Metro Man’s one weakness, Megamind’s plan to obliterate him with a death ray powered by the sun succeeds, and Megamind finally takes over the city.
His joy is short lived though, as without a hero to fight, he finds his life as a villain has become meaningless. He goes to the Metro Man Museum, which was dedicated to him on the day of his death and nearly runs into Roxanne. He uses his holographic watch to disguise himself as the museum’s curator Bernard, and she innocently gives him the idea of creating a new superhero to take Metro Man’s place.
After creating a formula from Metro Man’s DNA, Roxanne intervenes in his plans and he accidentally injects the serum into Hal Stewart, Roxanne’s dimwitted cameraman, who has an unrequited crush on her. Under the guise of his “Space Dad”, Megamind tries to mold Hal into a superhero named Titan, as it was the only name he could trademark but this was misheard by Hal as “Tighten”. Unfortunately, Hal’s ambitions are crushed when he sees Roxanne and Megamind as Bernard on a date. However, Megamind’s disguise malfunctions during dinner and she rejects him, causing him to lose track of his invisible car which contains the diffuser gun capable of removing Hal’s powers.
On the day of their planned battle, Hal doesn’t show up and Megamind finds that he has been using his powers for ill-gotten gains and wants to team up with Megamind to take over Metro City. Megamind informs Hal that he tricked him, revealing his Space Dad and Bernard disguises. This enrages Hal, and he tries to destroy Megamind, who activates a failsafe to trap Hal in copper as it was Metro Man’s weakness, but that too fails. After he escapes, Megamind pleads with Roxanne for help, and they go to Metro Man’s hideout to search for clues to why the copper didn’t work. Instead they find Metro Man, still alive; having felt pushed into the life of a superhero, he chose to fake his death (and by extension, his weakness to copper) so he could retire in order to do something that he wanted to do: pursue a career in music. He refuses to help despite the danger, but encourages Megamind that good will always rise up against evil.