At the end of the first "Guardians of the Galaxy" film, Peter Quill's motley crew headed back out into space, free of the weight of any past crimes -- and, when we find them in "Guardians of the Galaxy Vol. 2," they'll have a new mission: locating Peter Quill's father.
According to the film's synopsis, which surfaced on Stitch Kingdom,
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.
Antagonists Nebula and the Ravager Yondu will return and are likely to be the "old foes" that will ally themselves with the Guardians in "Vol. 2." While the synopsis doesn't reveal who these "fan-favorite characters from the classic comics" are, previous reports have pinned Elizabeth Debicki as Ayesha, who also goes by Her, Kismet and Paragon; if true, this could open the door to cult classic character Adam Warlock.