In order to get their hands on highly valuable Anulax Batteries, the Guardians — Peter Quill a.k.a. Star-Lord (Chris Pratt), Gamora (Zoe Saldana), Drax (Dave Bautista), and Rocket (Bradley Cooper) have to battle a huge beast, while caring for Baby Groot (Vin Diesel). They deliver the batteries to the Sovereign, but when Rocket steals some of the batteries, they find themselves in hot water.

While escaping the wrath of the High Priestess Ayesha (Elizabeth Debicki), Peter is contacted by his father, Ego (Kurt Russell), who has his own planet, where only he and his helper, Mantis (Pom Klementieff), live. Unsure whether Ego is a friend or a villain, the Guardians travel to his solitary planet so Peter can discover more about him. Meanwhile, Yondu (Michael Rooker) and his Ravagers want to get their hands on the batteries stolen by Rocket.