The mischievous Loki challenges the Marvel Super Heroes yet again. But this time, he's cast a snowball-themed spell that has Norn Frost in it to "Overload" various villains.
At a secret S.H.I.E.L.D. base in New Jersey, Doctor Octopus raids it in order to obtain the Beta Burst Missile. Using the Norn Frost obtained by his Chitauri minion, Loki "overloads" Doctor Octopus. In Manhattan, Nick Fury calls upon Spider-Man to help defeat Doctor Octopus. Before Doctor Octopus can use the Beta Burst Missile on the trapped S.H.I.E.L.D. Agents, Spider-Man arrives and tricks Doctor Octopus into shocking himself on a nearby power generator. The next morning, Spider-Man brings a bound Doctor Octopus back to Manhattan in a truck upon running out of web fluid on the Garden State Parkway. Nick Fury takes Doctor Octopus to be locked up as Spider-Man is left walking back to Queens, New York. Loki is not pleased that his Doctor Octopus "Overload" was defeated and vows that it's not over.
Some time later, news articles are shown about the "Overloads" like the rise of the Red Skull "Overload," the Wizard "Overload" forming the Frightful Sixteen which outnumbers the Fantastic Four, and the Green Goblin "Overload." J. Jonah Jameson reports on the "Overloads" and claims that Spider-Man is behind this. Loki then uses the Norn Frost on Venom since he is a creature worth overloading. Appearing near the stand of the Hot Dog Vendor, Venom is overloaded as Loki commands Venom to attack Spider-Man. Their fight takes them through the Daily Bugle much to the dismay of J. Jonah Jameson. Spider-Man manages to defeat Venom by getting one of Venom's tendrils into the Linotype machine where Venom ends up flattened onto a bunch of newspapers. Venom's body is taken away by Nick Fury, Captain America, and Wolverine. As Spider-Man swings away from the Daily Bugle, J. Jonah Jameson rants about his newsroom getting trashed as he vows to get Spider-Man for this. Spider-Man runs out of web fluid and falls into a dumpster leaving him to walk back to Queens again.
While reprimanding his Chitauri henchman for sitting in his chair, Loki sees a helicopter carrying Mandarin flying to Tony Stark's Malibu mansion to attack it. Loki then throws the Norn Frost at Mandarin who then prepares to attack. Iron Man saves Pepper Potts by getting her into an Iron Man armor. Iron Man then begins to fight Mandarin. As Loki plans to overload Mandarin further, his Chitauri minion slips and causes the Norn Frosts to fall into the nearby crevices. Iron Man uses his left glove to knock Mandarin out of his helicopter as he is grabbed by Falcon who takes Mandarin to the Helicarrier. Iron Man is then helped out of the rubble by his left glove before leaving with Pepper to eat out somewhere. Spider-Man suddenly finds himself at an offshore oil platform wondering how he got there.
While his Scrying Mirror is getting fixed, Loki reaches out with his mind where he finds Iron Man and Iron Fist looking for Abomination. Loki finds Abomination on top of a passing airplane as he overloads Abomination. Upon Abomination breaking the airplane, Iron Man and Iron Fist rescue the passengers and land them safely on the offshore oil platform while Hulk arrives to fight Abomination. With help from Iron Fist, Hulk knocks Abomination into the ocean. When Loki plans to overload Hulk to serve him, Hulk notices his floating eyes and punches it as Loki feels the pain while getting a black eye.
Loki declares that his plans are almost complete as his Chitauri minions sweep the floor. On the S.H.I.E.L.D. Helicarrier, Wolverine, Captain America, and Black Widow do a roll-call on the captive supervillains Doctor Octopus, Venom, Abomination, Mandarin, Red Skull, and Wizard. Loki then commands the supervillains to arise as they all end up overloaded again while being ordered to hop. The constant hopping causes the Helicarrier to fall onto Tony Stark's rebuilt mansion. The supervillains then go on a rampage as Iron Man, Nick Fury, Black Widow, Captain America, Wolverine, and Hulk fight them. Thor arrives with Spider-Man upon finding him whining outside Avengers Tower. Spider-Man claims that he was angsting. Upon taking down Doctor Octopus, Thor traces the Norn Frost back to Loki. Thor brings Iron Man and Spider-Man to Asgard to confront Loki while the others fight the supervillains.
Upon the Chitauri minions fixing the Scrying Mirror, Loki views it and sees Thor, Iron Man, and Spider-Man approaching his lair. Upon the arrival of Thor, Iron Man, and Spider-Man, Loki eats all the Norn Frost in the possession of one of his Chitauri minions and fights them. After throwing Spider-Man into a wall, Loki states to Iron Man and Thor that he is meddling in the affairs of Earth and take the throne of Asgard (Loki whispered that part which the Chitauri minion said out loud). Upon Loki slipping, Thor throws Mjolnir at Loki as he hangs over the crevasse. Thor then demands that Loki removes his enchantment and vow to never disturb the peace of Midgard under the threat of the hammer noogie. Loki surrenders where the Norn Frost's enchantment wears off enabling the supervillains to be defeated. Thor then plans to tell Odin what Loki was doing. Loki begs for Thor not to tell their father or to tell him that he was watching the Scrying Mirror since Odin took away his scrying privelages 3 centuries ago. After Thor, Iron Man, and Spider-Man leave, Loki changes the channel on the Scrying Mirror before Hulk can do another attack on him.
On the S.H.I.E.L.D. Helicarrier, the supervillains are locked up as they plan their revenge. On the deck of the Helicarrier, it was mentioned that Iron Man's mansion has been repaired and the Helicarrier is back on the air. To get the angst out of Spider-Man, Nick Fury gives Spider-Man a S.H.I.E.L.D. Security Card and a Spider-Bike. As Spider-Man rides the web line off the Helicarrier, the superheroes celebrate their victory. As the Helicarrier takes off, the web line breaks causing Spider-Man and the Spider-Bike to fall.
In the post-credits, J. Jonah Jameson is visiting the Hot Dog Vendor's cart ordering a hot dog from him. Spider-Man lands safely on the nearby streets as his Spider-Bike falls on the Hot Dog Vendor's cart. Getting mustard on him from the resulting incident, J. Jonah Jameson states that Spider-Man must be responsible as Spider-Man sneaks away.Laura Bailey - Black Widow
Dee Bradley Baker - Venom, Chitauri
Troy Baker - Loki
Drake Bell - Spider-Man
Steven Blum - Wolverine
Greg Cipes - Iron Fist
Grey DeLisle - Pepper Potts
Barry Dennen - Mandarin
Robin Atkin Downes - Abomination
Tom Kenny - Doctor Octopus
Stan Lee - Hot Dog Vendor
Tony Matthews - Jogger
Chi McBride - Nick Fury, Red Skull
Adrian Pasdar - Iron Man
Bumper Robinson - Falcon, S.H.I.E.L.D. Sentry
J.K. Simmons - J. Jonah Jameson
Roger Craig Smith - Captain America
Fred Tatasciore - Hulk, S.H.I.E.L.D. Sentry
Travis Willingham - Thor