Avengers: Infinity War left audiences with a surplus of questions after the film ended, but that’s exactly how it was designed.

[Warning: The following includes spoilers for Avengers: Infinity War.]

Writers Christopher Markus and Stephen McFeely spoke about their original plans for Avengers 4 in a new interview with the New York Times. Markus and McFeely always knew they wanted to end with Thanos’ climactic snap erasing half the universe. There was some conversation about moving the scene to Avengers 4, but they decided against it.

Allowing Thanos to morph into this powerful being, and demonstrating that power before Earth’s mightiest heroes, allowed Markus and McFeely to have one movie “that went all the way to a tragic ending. And then one where mysterious things happen that I can’t tell you about.”

Little is still known about Avengers 4, but McFeely said Captain America and Black Widow “have a much bigger role to play in that second film.”

Infinity War ended with most heroes — and humans, in general — fading into the abyss. The original Avengers are still alive (minus Hawkeye, who didn’t appear in the movie), and a few other straggling characters but 50 percent of the fighting team is gone. It’s up to the Avengers and their friends to figure out what happened, stop Thanos and hopefully find a way to reverse his decision that also brings their friends back.

Not every superhero is going to return and, of those left, not every person is going to survive. Fans are already feeling pretty emotional; after all, we’ve watched these superheroes grow as characters for 10 years. Both Markus and McFeely are aware of the emotional impact Infinity War has on people, joking about mean tweets they’ve stumbled upon or messages they’ve read. Although they feel bad, Infinity War is just one part of the puzzle.

“It’s just the one where the bad guy wins,” Markus said.

Avengers 4 will be released on May 3, 2019.