This issue was part of the “Endless Winter” mini event.
Story continued from the following issues:
Chapter 1: Justice League: Endless Winter #1
Chapter 2: The Flash #767
Chapter 3: Superman: Endless Winter Special #1
Chapter 4: Aquaman #66
Chapter 5: Justice league #58
Chapter 6: Teen Titans: Endless Winter Special #1
It continued in the following issues:
Chapter 8: Black Adam: Endless Winter Special #1
Chapter 9: Justice League: Endless Winter #2
Diana and the others learn the history of the Frost King from Hippolyta, and how the Viking King Jon had sacrificed himself to take him down. Wonder Woman and Zatanna travel to enlist the help of Swamp Thing and The Green, while Hippolyta summons the spirt of the Viking King who reveals that in the last few moments of his life he had seen Frost King’s real self, Edwald Olafsson, pleading for help to save his family.
When Wonder Woman and Zatanna return with a piece of The Green, it bond with the spirit of the Viking King to create a new Swamp Thing.