Thor: The Dark World (2013)

Thor: The Dark World is the second Marvel Cinematic Universe installment who explicitly reveals an Infinity Stone: the Aether.

In Asgard, Thor has become the noble leader his father wanted him to be. Loki, after the failed invasion of Earth, is in a jail. But when Malekith the Accursed threatens to plunge the whole universe into darkness, he teams up with his step-brother in order to stop the evil Dark Elf.

The fight takes place in London and, eventually, Thor subdues his opponent. Loki is believed dead by his fellow Asgardians, after facing the powerful Kurse – little does anybody know, since he took the place of Odin on the throne, with the latter being presumably killed. It isn’t known yet whether or not Loki is still working for Thanos.

Thor: The Dark World also introduced the Collector into the Marvel Cinematic Universe, who may or may not work for the Mad Titan. What is known until this point is that he is entrusted with the Aether, since Asgard is proved to be unsafe for storing two Infinity Stones. Introduction of the Collector also means that the shared Universe has expanded even further, in a way announcing the appearance of another team of superheroes.