Emma, Regina, Mary Margaret, David, Robin, Henry and Gold arrive in the Underworld, on a mission to rescue Hook, only to discover that their search will be more difficult than they had anticipated. The inhabitants of the Underworld — all souls with unfinished business and many with quite personal vendettas — hound our heroes at every turn. Meanwhile, in an Enchanted Forest flashback, a familiar face from the Evil Queen’s past returns to present Regina with the perfect birthday gift.