After the earthbound heroes went on a royal rumble in "Captain America: Civil War," the more powerful, cosmic beings face off in "Thor: Ragnarok."
At the end of "Thor: The Dark World," we find out that Odin is not the one sitting on the throne in Asgard but a shape-shifted Loki. Thus, the big question was Odin's location and condition. There were many theories brought forth based on the comic books from being dead to undergoing the "Odin sleep."
However, recent revelations on the plot has Odin trapped in Midgard, based on behind the scenes photos as featured in Screen Rant. As they point out, the setting is New York with taxis and establishments bearing New York signage, even though they were actually shot in Australia.
This led to the mid-credit scene where Thor and Doctor Strange discussed the presence of Loki in Midgard. There were scenes where Thor and Loki were together, and that could mean two things: the "brothers" were searching for their father together (as Thor may still not know that Loki has turned evil again after they worked together in 'The Dark World') meaning Loki does not know what happened to Odin (and therefore, he wasn't responsible for it. Or it could also be an act (he's not the god of Mischief for nothing).
One person who could see through it all would be Doctor Strange. No less than Tom Hiddleston mentioned it in an interview during the Golden Globes from MTV.
"I can't spoil anything for you," Hiddleston said. Yet he talked about the role of Doctor Strange in "Thor: Ragnarok."
"Doctor Strange has very intensely, cerebral, time-bending powers," Hiddleston says. "At the end of Thor: The Dark World Loki's on the throne. What happened to Odin? So, maybe Doctor Strange has to help out with that particular conundrum."
Hiddleston was pushed but he somehow dodged a direct meeting of Doctor Strange and Loki, but his defense reveals that it could actually happen. As the interviewer noted, it's almost a "no-brainer" to have the Sorcerer Supreme face off with Loki.
It was clear that Doctor Strange saw the Asgardians as a threat and he didn't want them wandering around "this world" as shown in the mid-credits scene in "Doctor Strange." What if Loki has plans to stick around?
If Thor vs Hulk was not reason enough to watch "Thor: Ragnarok" the Loki-Doctor Strange face-off takes the cake.