Whenever you watch a major action set piece in a modern movie, you are watching a sequence that probably came together months before the cameras started rolling. Complicated effects-driven scenes are often assembled in an early rough form so that the actual shooting of the scene can go smoothly. Avengers: Age of Ultron was no different; to watch the animatic of the massive battle between Iron Man and the Hulk is to watch how an action scene can change from origin to execution.

The basics are still the same. The Hulk, driven to madness by the Scarlet Witch, is still rampaging through the streets. Iron Man, breaking out his new anti-Hulk armor (nicknamed “Veronica”), still flies in to stop him. But the little details are so very different. The dialogue got a rewrite between this animatic and actual production. The choreography got shuffled. Beats and gags got removed (Hulk never uses a light post as a baseball bat) or modified (the cage gag from the beginning is now an electrified fence with gas). There’s even a fun shawarma cameo! This animatic often feels like a completely different fight and it’s fascinating to watch carefully and note what got changed.

And while the rough look of the animatic is entirely about getting the sequence assembled as quickly as possible, watching the hand-drawn Hulk battle the CGI Iron Man is a genuinely nifty image. It almost looks like, well, a comic book. How appropriate.