In the realm of Asgard, the powerful and arrogant warrior Thor is set to ascend to the throne. His father, King Odin, oversees a peaceful and prosperous kingdom. However, Thor's rash behavior reignites an ancient war. As a result, Odin banishes Thor to Earth as punishment, stripping him of his powers and his mighty hammer, Mjolnir, which now is enchanted so that only the worthy may lift it. On Earth, Thor crashes into the New Mexico desert where he is discovered by astrophysicist Jane Foster, her assistant Darcy Lewis, and mentor Dr. Erik Selvig.

Struggling to adapt to his new mortality, Thor seeks to reclaim Mjolnir and return to Asgard. On Earth, his hammer attracts the attention of government agency S.H.I.E.L.D., which takes possession of both the hammer and Jane's scientific findings related to the atmospheric disturbances caused by Thor’s arrival. As Thor attempts to retrieve his hammer, he begins to learn humility and develops a close connection with Jane and her team. Back in Asgard, Thor's brother Loki uncovers a secret that leads him to plot to take the throne for himself, placing Asgard and Earth in great peril. Thor must confront his own shortcomings and rise to the challenges of potential heroism to thwart his brother's schemes and protect both worlds.