Spoilers for Guardians of the Galaxy Vol. 2 follow.
The first Guardians of the Galaxy established that Quill's mother died of brain cancer. Peter was then picked up by Yondu and the Ravagers, who were supposed to deliver the boy to his father, whom we now know is Ego the Living Planet.
That much remains true, but it wasn't the whole truth. Peter finally meets his father in Guardians of the Galaxy Vol. 2. Peter listens to Ego tell of how much he loved Peter's mother. Ego even puts Peter under his cosmic thrall so that he can enact his cosmic plan, "the expansion."
Ego's mistake comes when he reveals the truth about how Peter's mother died. Yes, she died of brain cancer, but it turns out that Ego put the tumor in her brain so that she would die and he would no longer be tempted to stay on Earth with her.
This revelation is enough to snap Peter out of his cosmic trance and he immediately opens fire on Ego. Of course, Ego is a Celestial, so that doesn't have much effect, but this bomb drop launches Guardians of the Galaxy Vol. 2 into the massive final battle that makes up its third act.
In the end, Peter Quill's mom didn't just die of brain cancer. She was murdered, and the tumor was the weapon.
Guardians of the Galaxy Vol. 2 currently has an 87.36 ComicBook.com Composite Score, the fourth-highest ComicBook.com Composite Score for a comic book movie of all time. Guardians of the Galaxy Vol. 2 also has a 4.54 out of 5 ComicBook.com User Rating, giving it the second-highest ComicBook.com user rating among all comic book movies. Let us know what you thought of Guardians of the Galaxy Vol. 2 by giving it your own ComicBook.com user rating below.
Set to the backdrop of 'Awesome Mixtape #2,' Marvel's Guardians of the Galaxy Vol. 2 continues the team's adventures as they traverse the outer reaches of the cosmos. The Guardians must fight to keep their newfound family together as they unravel the mysteries of Peter Quill's true parentage. Old foes become new allies and fan-favorite characters from the classic comics will come to our heroes' aid as the Marvel cinematic universe continues to expand.
Guardians of the Galaxy Vol. 2 is written and directed by James Gunn and stars Chris Pratt, Zoe Saldana, Dave Bautista, Vin Diesel, Bradley Cooper, Michael Rooker, Karen Gillan, Pom Klementieff, Elizabeth Debicki, Chris Sullivan, Sean Gunn, Sylvester Stallone and Kurt Russell.
Guardians of the Galaxy Vol. 2 is now playing in theaters.
MORE GUARDIANS OF THE GALAXY VOL. 2: Did Marvel Make A Deal With Fox For Guardians Of The Galaxy Vol. 2 Characters? / Dave Bautista Teases New Characters In Infinity War / Dave Bautista Thinks Marvel Studios Can Get Back Spider-Man / Surprising Thor: Ragnarok Character Cameos In Credits