In an interview with SFX Magazine, Thor: The Dark World director Alan Taylor revealed that The Avengers: Age of Ultron writer/director Joss Whedon arrived on set in London at the last minute to help him out of a rough spot.
There were three different scenes in the screenplay that weren't working on the page, so Joss was flown to the set to help out with the problem, showing how much of a team effort these Marvel Universe movies truly are.
Here, Alan Taylor describes how it all went down.
"Joss came in to save our lives a couple of times. We had a major scene that was not working on the page at all in London, and he basically got airlifted in, like a SWAT team or something. He came down, rewrote the scene, and before he got back to his plane I sort of grabbed him and said, 'And this scene and this scene?' And he rewrote two other scenes that I thought had problems. Then finally we let go of him, he took off again, and we shot the scenes; and they were just much better and much lighter on their feet. Much more fun, much more surprising than what we had been trying to do."
Its not a secret that reshoots were recently done on the upcoming November release. Most of the new scenes were added to flesh out the fan-favorite characters of Tom Hiddleston's Loki and Kat Dennings' Darcy Lewis. In a https://movieweb.com/thor-the-dark-world-reshoots-include-an-idea-pitched-by-tom-hiddleston/story from September 9, it was revealed that Hiddleston also contributed to the screenplay, with some of the reshoots focusing on scenes the actor himself created.
The reshoots have not been pitched to the public as fixing a troubled movie. Instead, Marvel is selling it as an 'expansion pack of extra moments for the fans'. We'll probably have to wait until closer to the release date to find out which scenes are specifically from Tom Hiddleston and Joss Whedon. Hopefully it all makes this movie better, instead of offsetting the tone in four or five different moments throughout the finished product.