10 MCU Loose Ends That Will Mean Something In Phase 4

9. What Happened In Budapest?

Much like the Kessel Run, the mission in Budapest that seemingly drew Hawkeye and Black Widow together closer than ever has hung over the MCU like an enigmatic secret that never really NEEDED to be explored further. It was always a gag that hinted at a shared past - and different perceptions of the experience - to set up the pair's personalities and give them something more than "just" superpowers.

Still, it's a question that fans have somewhat understandably picked up on since The Avengers and even though Black Widow is now dead, we're finally getting an answer to why Budapest is important. We might not get an actual flashback to Back Widow and Clint on their mission there, but Natasha is returning there for her solo movie and we will presumably get to see the film exploring some of the fallout from what happened back then.