It’s arguably the most famous ending to any Marvel Studios movie — perhaps any superhero movie, period — but, according to Avengers: Infinity War and Avengers: Endgame co-writer Stephen McFeely, the Snapture almost didn’t happen in Infinity War at all.


“We had so much story in those early drafts of Infinity War that, if anything, we thought we maybe shouldn’t do The Snap until the end of act one of Endgame,” McFeely told Empire in a recent interview.


The reason it didn’t happen, Marvel Studios CEO Kevin Feige revealed, was that, for him, Thanos (Josh Brolin) killing half of all life “was the reason to adapt Infinity Gauntlet [the 1991 comic book storyline]. What was the most shocking thing we could do? End the movie with The Snap.”


The idea of not ending on Thanos’s Snap is such an unexpected one, because it’s clearly the obvious cliffhanger in the story; you end Part 1 where everything is at its worst, and it doesn’t get much worse than “More than half of the heroes have died as the result of the villain gaining effective omnipotence.” To hold that over to the end of the first act of Endgame essentially wastes the torture audiences have felt for the past ten months, wondering just how everyone comes back to life and the day gets saved. (I’m giving audiences credit for not actually believing all the deaths will stick.)


Not only that, but removing the snap from the end of Endgame also raises the question, “Just when would that movie have ended, otherwise?” Beyond the obvious “Part 1 of a massive crossover story intended to feature all the Marvel heroes in the same story for once” construction, Infinity War is a story about Thanos gathering the final ingredients to complete his master plan. The obvious place to end the movie is with that master plan either succeeding or failing — where else could the story end, realistically?


Think about Infinity War as it currently exists, however; Thanos snaps everyone out of existence upon getting the final stone, which is also the big climactic battle with the good guys — did all of that exist in the first act of Endgame at one point, and if so, does that mean Infinity War had a version that didn’t include any kind of climactic event? Was the story simply that Thanos got some of the Infinity Stones, and then… glowered menacingly at the camera that, next time, he would really do something? Isn’t that just what the post-credit sequences of Avengers and Avengers: Age of Ultron offered, in far shorter form?


But consider the alternative: An alternate version of Infinity War in which the heroes did face Thanos and get their asses kicked, but the snap didn’t happen. The breakneck pace of the movie would have stalled with the introduction of a delay between meeting Thanos and failing to prevent the snap from happening; and there’s no version of a story where Thanos got all the stones and didn’t snap works.


In other words, Feige had it right; Infinity War had to include the snap as its capper. McFeely’s comment is, nonetheless, instructive in an entirely different fashion: If the snap could have existed at the end of the first act of Endgame, does that mean there’s not too many twists and turns left ahead of the big finale? That seems unlikely.


Avengers: Endgame is released April 26.