Hades turns to the heroes to ask for help with getting Zelena back from Rumplestiltskin and Peter Pan. In flashbacks, Emma searches for answers about her family and makes an unexpected friendship.
Now that Hades and Zelena have been reunited, Hades tells Zelena about his plan to leave the underworld forever and Cora reveals information from the past that will change the lives of Regina and Zelena forever.
In flashbacks, Ruby and Mulan find themselves in Oz, where they meet Dorothy. After the three witness Zelena's return to Oz, they look for a way to defeat her once and for all. However, Dorothy mysteriously disappears
Belle turns to Rumplestiltskin with hope of finding a way to protect their child from Hades. However, they disagree over whether to use dark magic, as Belle forbids Rumplestiltskin from using his powers for evil.
Gold creates a Storybrooke portal; Zelena and Regina clash; Belle and Rumple are reunited; Snow and David try to send a message from the Underworld to their son, Neal.
After rescuing Hook, Emma works with her lover to find a way out of the Underworld. However, the group is unaware that Hades means to turn them against each other and trap them forever. In the past, Killian and Liam's bond is tested during a storm at sea.
Hook's captivity takes a dark turn when Hades threatens to condemn him to the River of Lost Souls after Hook refuses to choose which three of his friends will have to remain in the Underworld.
The heroes join forces with an old friend of Snow's to defeat an obstacle standing in the way of finding Hook. Meanwhile, Hook encounters challenges of his own.
