One Mind Blowing Secret From Every MCU Movie

By the time Avengers: Infinity War rolled around, Thanos (Josh Brolin) had been hiding in the shadows of the MCU for some time, and it had been even longer since Titan had crumbled as he prophesied. Such begs the question, why did he begin his Infinity Quest now?

The Age of Ultron's post-credit scene, in which Thanos grabbed the gauntlet and proclaimed that he would do it himself, sticks out like a sore thumb, because it really has nothing to do with anything. What actually kicked off the chain of events was Nebula (Karen Gillan).

At the end of Guardians of the Galaxy Volume 2, Nebula put Thanos in her crosshairs. This is when her father caught her on board her ship, and as confirmed by the director's commentary on Infinity War, this is where Thanos finally learned that Gamora (Zoe Saldaña) knew where the Soul Stone was, and so he could begin his plan.

Everyone turned on Star-Lord when he woke Thanos up just before the Avengers were able to get the gauntlet off his giant, purple mitt, but what Nebula did was so much worse. Had she just left Thanos be, or at least successfully killed him, none of Infinity War would have come to pass.