Having saved the cosmos after the events of Guardians of the Galaxy (2014), the Star-Lord's now famous intergalactic defenders find themselves with their backs to the wall after the Battle of Xandar.
And having failed to protect the Anulax Batteries, the most potent source of energy in the entire universe, the Guardians have made a new enemy: Ayesha, the Golden High Priestess of the technologically advanced, genetically engineered extragalactic race known as The Sovereign.
To top it all, the team has a chance encounter with a mysterious being named Ego and a hard-as-nails character from the past. With their lives hanging by a thread, can the Guardians of the Galaxy save the world for the second time?