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.
