The filmmakers responsible for the MCU knew Thanos was coming long before we did. There are moments throughout Marvel's movies that go by in the blink of an eye, but are actually very important to the big picture - we just didn't know it yet. Here’s your Spoilers ahead! Warning we are saying what’s important to Endgame - we think - but we aren’t spoiling specific plot points to Endgame. We’re just using the clues from past films. So you’re safe... unless we’re right about everything, and if so… oops! It's an easy thing to forget: Behind his high-tech armor and sarcastic facade, Tony Stark is still only human. He's not physically the strongest of the Avengers that would be the Hulk, obviously — but Stark certainly has the strongest personality. Tony Stark's plucky personality makes it easy to forget that he's ultimately fallible. Rather than being all wit and one-liners, Tony struggles with a feeling of powerlessness after the Battle of New York, and it's a feeling that we would never have associated with such a powerful figure. In Iron Man 3, Tony has flashbacks to the black maw of the wormhole that he never thought he'd come out of. His knowledge of the reality of what's out there in space especially civilizations with bigger, badder weapons haunts him, plaguing him with PTSD flashbacks and nightmares. In Avengers: Age of Ultron, this fear of the danger lurking in space manifests in the nightmarish hallucinations that Scarlet Witch subjects him to. Tony sees Black Widow, Cap, Thor… all of his friends... broken and dead. In a way, this turns out to be a vision of the future. In Infinity War, as hard as he tries, Tony is unable to stop Thanos from getting the final Infinity Stone needed for the big Snap. He watches in horror as his friends fall around him, while he stands powerless.