There have been a lot of important scenes in the history of the Marvel movies: The first time Robert Downey Jr. said “I am Iron Man”; the debut of Thanos in the end credits of The Avengers. But if we had to credit one scene that truly began the Marvel Age of Movies, it would have be something from well before the Marvel Cinematic Universe even existed.

We’re talking about a scene from the original X-Men, and in this new video from ScreenCrush’s Ryan Arey, we break down just why this sequence is so. important to the film and to the overall history of Marvel onscreen. It’s part of a YouTube playlist called “One X-Cellent Scene,” where various channels are putting a spotlight on important moments in the history of the Fox X-Men franchise.

Watch ScreenCrush’s One X-Cellent Scene right here:

If you liked this video on the most important scene in the original X-Men, check out more of our videos below, including our essay on the secret meaning of Spider-Man: Far From Home, our essay on what makes Iron Man works (and makes Man of Steel not work), and our theory about Obadiah Stane and Hydra. Plus, there’s tons more over at ScreenCrush’s YouTube channel. Be sure to subscribe to catch all our future episodes.

Gallery — The Evolution of Every Avengers Costume, From Movie to Movie:

More From ScreenCrush