Everything in the Marvel Cinematic Universe seems to come down to one man—Tony Stark.

The man started it all in Iron Man back in 2008, and has continued to lead the Avengers as the MCU grows 20 movies deep. As we shift through the events in Avengers: Infinity War and past Marvel movies, more hints reveal the events for Avengers 4 were being laid down long before Thanos got his hands on all six Infinity Stones.

One of the movies is Avengers: Age of Ultron. If you remember, the Avengers become upset with Tony Stark after the artificial intelligence he created becomes Ultron, a diabolical robot hell bent on eradicating humanity due to its imperfection. In one exchange in particular, the words he uses parrallel words used in Infinity War.

“A hostile alien army came charging in through a hole in space,” says Stark. “We’re standing 300 feet below it. We’re the Avengers. We can bust arms dealers all the live-long day, but that up there? That’s the endgame. How were you guys planning on beating that?”

The word endgame stands out because Doctor Strange uses the exact same word in Infinity War when he hands over the Time Stone to Thanos to spare Tony Stark’s life. When Tony asks him why he did it, Strange responds, “We’re in the endgame now.” Moments later, Strange along with most of the Avengers turn into dust.

The move was the only one of over 14 million scenarios Doctor Strange saw (using the Time Stone) that would lead to Thanos’ defeat. At the time the words were uttered not even Tony Stark understood the meaning, but he will the once events kick off in Avengers 4.

Handing over the stone to Thanos ensured Tony Stark would live, but it also cost Doctor Strange his life. He understood at this point Tony Stark’s life was more important than his.

It’ll be interesting to see how the Russo brothers payoff the connection between Age of Ultron and Infinity War in Avengers 4 and possibly continue or conclude Tony Stark’s arc within the MCU.