Iron Man, Spider-Man, Hulk and Thor stand powerless after being struck by Dr. Doofenshmirtz's power-draining "inator." Once the Marvel Super Villains - Red Skull, Whiplash, Venom and M.O.D.O.K. - find out that Dr. Doofenshmirtz is responsible for robbing the Super Heroes of their powers, they seek him out and together create mayhem in Danville. Meanwhile, Phineas and Ferb do everything they can to restore the Super Heroes' powers before the evil villains take over the world.
"Aunt May, Phineas and Ferb are making a crossover!"
Hulk has lost his strength.
Spider-Man lost his powers.
"Ferb, I know what we're gonna do today! Hehehehehe!!"
"Is he some kind of super-platypus with super-platypus powers?"
Isabella giving Iron Man a juice box.
Ding dong. Avengers calling.
Doofenshmirtz with MODOK and Red Skull.
The heroes confront the villains.
Venom, Modok, Whiplash, Red Skull and Doof do all sorts of evil around Danville.
Doof and Red Skull in a ballpit?
Spider-Man, Spider-Man, does whatever a spider can.
MODOK, Venom, Whiplash, Red Skull and Doof marching and stomping on a flower bed.
Phineas space surfing in the opening.
Isabella and Phineas holding hands.
It's a bird! It's a plane! It's a platypus!
Phineas and Ferb: Mission Marvel.
Candace cheers for the Superheroes.
Candace gets upset, and Phineas is so mad that he points her to the door to get out.
Candace faints after seeing Ducky Momo in the Costume; Isabella catches Candace as she faints.
Nick Fury & Monogram warning Agent P.
Super Heroes rescued by Perry The Playtpus.
Doofenshmirtz attacking from his building.
Quack quack Ducky Momo-san superhero desu!
Stan Lee gets a little annoyed with Dr. Doofenshmirtz.