Warning: SPOILERS for Avengers: Infinity War are ahead!
We have James Gunn to thank for bringing the Guardians of the Galaxy to life in the Marvel Cinematic Universe, and while he didn't write or direct Avengers: Infinity War, Gunn did contribute to the movie as an executive producer, which included him writing some dialogue for the Guardians and suggesting songs for Peter Quill to listen to on his Zune. Now we've learned that both Gunn and Quill's actor, Chris Pratt, were adamant on one key moment in Infinity War unfolding the way it did: when Quill, a.k.a. Star-Lord, made the heartbreaking decision to try to kill Gamora so that Thanos couldn't interrogate her. Unfortunately for Star-Lord and Gamora, that didn't work out the way they planned, but we could have gotten a version of the scene where Star-Lord wouldn't have pulled the trigger at all. Infinity War co-writer Stephen McFeely explained:
The only change [James] really went deep on and we had more than one conversation about was the decision by Star-Lord to shoot Gamora and then bubbles come out obviously. So we wrestled with, 'Would it be interesting if Star-Lord could not bring himself to fulfill his promise and kill the woman he loves?' It's not a traditional hero arc. We were trying to get to a failure [moment] because his love for her outweighed his duty in some ways. And Gunn and Pratt were really adamant that he would do it. So we did it, and of course, it didn't hurt our story to do it, because it's not gonna work.
For those who need an Avengers: Infinity War refresher, before arriving Knowhere to try to reach The Collector and the Reality Stone before Thanos did, Gamora told Peter Quill that if Thanos captured her, she wanted Quill to kill her, as she had information that the Mad Titan could never know, and she refused to tell Quill for fear of him being targeted as well. Upon arriving at Knowhere, Gamora was tricked into thinking she had successfully killed Thanos, but it was all a ruse, as he had already taken the Reality Stone from Collector. He subsequently took Gamora hostage, and after confessing his love for her, Quill tried to kill her to respect her wishes, but Thanos used the Reality Stones to make bubbles come out of the blaster instead.
Had James Gunn and Chris Pratt not spoken to Stephen McFeely and Christopher McFeely, the writers may have decided to have Star-Lord not kill Gamora to show vulnerability, but since James Gunn and Chris Pratt were more familiar with these characters, they suggested going in the opposite direction, and as McFeely told Backstory Magazine (via The Playlist), it ended up working for the story. And Star-Lord still had his 'mistake' moment in Avengers: Infinity War, as when he later learned that Thanos had killed Gamora to obtain the Soul Stone, he grew enraged and retaliated against Thanos, which allowed the villain to break free from the hold the heroes had over him and wipe the floor with them.
By the time Avengers: Infinity War ended, the only Guardians of the Galaxy left alive were Rocket and Nebula, with Star-Lord, Drax, Groot and Mantis having been erased from existence along with half of life in the universe by Thanos. We'll see how this tale and the MCU's Phase Three concludes when Avengers 4 is released on May 3, 2019.