Loki is secretly a twin, not even he knows because they were separated at birth. Loki is now an Avenger with his brother, Thor.

Odin finds lokis twin, he calls for Loki and Thor to Asgard. Even allowing the Avengers to go to Asgard as well. So they all go, not knowing why Odin's called them to Asgard.

As they get to Asgard, they go to the throne room, where Odin sits on his throne. Waiting for them.