In a rage, Quill attacks The Mad Titan and creates an opening for Thanos to get the Infinity Gauntlet back and finish his mission.
First, let’s make sure everyone is up to speed.
Victory seems assured for the group until Star-Lord notices that Gamora is missing.
Suspecting the worst, his fears receive confirmation when Nebula explains that he left with Gamora and came back without her but with the Soul Stone, the implication being that he murdered her on Vormir to obtain the mysterious gem.