The Avengers: Earth's Mightiest Heroes!

Synopsis

An arctic expedition somewhere in Norway is led by masked man. While exploring a gated off cave, they discover the remains of several frozen ancient vikings, scaring off the majority of the exhibition team. Their mysterious leader goes further into the depths of the cave, discovering an innocuous looking small treasure chest.

Meanwhile, in New York City, several Avengers (namely the Wasp, Hawkeye and Hulk) are enjoying a warm summer day while Thor, Iron Man and the Black Panther battle the Radioactive Man. During the fight, Iron Man and Thor debate the merits of science and technology, with Thor arguing that mortal science only causes harm.

Back in Norway, the mysterious man is joined by Enchantress and Skurge the Executioner. It is revealed that the mysterious man is Malekith, and that Loki tasked him with retrieving the small chest he had discovered, believed to be the infamous Casket of Ancient Winters. Before handing it over to Enchantress, Malekith opens the casket, instantly freezing both Skurge and Enchantress as well as releasing a massive winter storm that soon covers the entire Earth.

As Thor and Iron Man continue their scientific argument, the storm released by Malekith reaches New York City, quickly covering the entire city in snow. Thor quickly surmises that the storm is caused by the Casket, recalling that his father Odin hid it on Earth ages ago. Iron Man angrily continues his earlier debate with Thor, arguing that clearly this current turn of events proves that the magic that the Asgardians believe in is more dangerous than any Earth science. Before their verbal fight becomes too heated, Black Panther is able to pinpoint the Casket's location. While the rest of the Avengers battle ice monsters summoned by Malekith, the trio of Thor, Iron Man and Black Panther fly to Norway.

In Norway, the trio find the Casket and Malekith. The Dark Elf reveals his plan to turn Earth into the new realm of his people, using the Casket to weaken the current inhabitants of Earth to more easily conquer them. A battle ensues between the Avengers and Malekith, but it soon becomes clear that none of the heroes can defeat Malekith on their own. Eventually the Black Panther suggests that Iron Man and Thor combine their magical and technological abilities, overwhelming Malekith and closing the Casket. Soon, the winter storm clears and the monster Malekith summoned are banished.

Thor and Iron Man agree that it was their mutual skill and gifts that allowed them to defeat Malekith. Before they can retrieve the Casket, however, Enchantress and Skurge (unfrozen when the Casket was closed) take it for themselves. Enchantress tells Thor "It will all be over soon," and then disappears along with Skurge into a portal. When Thor attempts to open his own portal to Asgard, he is unable to enter it, aware that he has been blocked from his home realm by "a power far greater" than his.

Production Notes

This and several subsequent episodes first premiered on Australian television in April, 2011; it first premiered in the United States in May of the same year, scheduled to release the weekend following the release of the Thor film.

There are some small differences between the two broadcasts. A short "Previously on Avengers" segment was added to the beginning of the episode, recapping the previous Asgardian stories from earlier in the series. This may be due to the long gap between when the show had been previously on the air in the United States; in Australia, the entire first season was shown in barely over a month (March 8, 2011-April 12, 2011). Also, the title sequence was significantly shortened (possibly due to the time needed to add the "Previously On" sequence) and given a voice over narration to describe several members of the Avengers.

The American broadcast is the first to include an Executive Producer credit for Jeph Loeb.

The narrator for the US opening and a short vocal cameo for Ben Grimm/The Thing are not listed in the cast credits; it has been suggested by various online sources that The Thing's voice is done by Fred Tatasciore, the same actor as the Hulk.