As our heroes set out to stop Hyde, Emma develops a mysterious side effect, and Storybrooke becomes a haven for refugees from the Land of Untold Stories. Meanwhile, Regina and Zelena embrace their newfound sisterhood by becoming roommates, while Rumple tries to free Belle from the sleeping Curse with the help of a stranger. In flashback, Jafar confronts an afflicted Aladdin in Agrabah, and a secret about the Savior is revealed.

Princess Jasmine recruits Aladdin to help her recover a secret weapon capable of breaking Jafar's hold on the Sultan and saving the city from ruin. In Storybrooke, the Evil Queen tricks Hook and the Charmings and forces Emma to reveal her secret in an effort to divide the family.

Emma tries to convince Aladdin to work with Jasmine to help Agrabah, while Regina teams up with Snow and David to free Archie from Zelena. Meanwhile, in the past, Hook finds himself kidnapped by the mysterious Captain Nemo and held captive aboard his submarine, the Nautilus.

Emma and Regina formulate a plan to trap the Evil Queen in a prison of their own making, while Snow and David adjust to life without each other. Meanwhile, Zelena agrees to help Belle, and together they enlist Aladdin to steal a magical object from Mr. Gold that could protect Belle and her unborn child from him forever.

Gold tells the Evil Queen she must kill Zelena, and the Queen makes a decision that will change her relationship with her sister forever. When Belle discovers Gold's plans for their son, she convinces Hook and Emma to help her steal squid ink that can immobilize him. Meanwhile, Jasmine finds a genie-less lamp that she hopes to use to save Agrabah.

When she learns the heroes possess a weapon capable of defeating her, the Evil Queen steals Aladdin's magic lamp from Jasmine and makes a wish that could sideline the Savior forever. Unwilling to wake Snow while Emma is missing, David works with Hook and Henry to hold the Evil Queen at bay in Storybrooke.

When Hook finds himself trapped in another realm along with the Nautilus and her crew, he races to return to Emma before Gideon can execute the rest of his plan. In Storybrooke, Regina and Snow take Emma out to get her mind off Hook's disappearance. And in a flashback to Agrabah, Jasmine befriends Ariel, and together they set out to locate Prince Eric as the threat from Jafar intensifies.

Henry wakes up in a strangely changed Storybrooke where Emma is a mental patient and the rest of his family has disappeared.

Emma regains her memory but discovers that the Black Fairy has set the perfect trap for her. Meanwhile, the Evil Queen makes the ultimate sacrifice to save her former kingdom, and Gold is forced to choose between Good and Evil.