One of the best and most crowd-pleasing moments into Avengers: Endgame has to be Cap vs. Cap. For all the rumors and fan theories that had been swirling around the fourth Avengers movie before we even knew the title, seeing Chris Evans go toe-to-toe with himself was a total shock.

But how did they do it? On the latest episode of Earth’s Mightiest Show, Marvel’s Ryan Penagos chats with Endgame visual effects supervisor Dan DeLeeuw to break down how this instantly-iconic scene was put together.