10 MCU Plot Holes That Aren't Actually Plot Holes
7. Thor Returns To Earth Even Though The Bifrost Bridge Is Gone - The Avengers
At the end of Thor, the titular god gets into an emotionally-charged scrap with his (sort-of) brother, Loki.
The ensuing fisticuffs results in the Bifrost Bridge - the gateway that leads from Asgard to the other realms - being destroyed.
We're told there's no way Thor will be able to return to Earth as a result of this, so it was surprising to see him pop up on Earth, with little explanation, in The Avengers. How did he make this journey without the Bifrost?
This has been a big point of contention over the years, but it's important to point out that although the explanation offered by the movie is flimsy, it's an explanation nonetheless.
Loki asks Thor how much "dark energy" the all-father had to summon to send Thor to Earth, which indicates that this was a dangerous, possibly frowned-upon process, one that Odin only pulled off out of desperation.
This was more-or-less confirmed by Chris Hemsworth, who stated that Odin had to call in several favours from the other realms.
Or, to put it another way, this is not something that usually happens, something that Odin wants to do, or even something that he would mention; all he wants is for Loki to be brought to justice, and so does whatever he can to see that through.
Plus, it's never stated that the Bifrost is the only way for Asgardians to get to Earth. Just because we're never told about another method in Thor, doesn't mean there isn't one... and clearly there is!