<Tr> <Td_colspan="7"> Back in the Enchanted Forest, Hook's feelings about his father abandoning him as a young boy lead to Hook killing him when Regina recruits him to kill Cora . In Storybrooke, as Hook and Nimue prepare to send Emma's family and friends to the Underworld to allow the resurrected Dark Ones to stay, his memories remind him of the man he wants to be . When he realizes what will happen if he goes through with it, Hook turns Excalibur on the previous Dark Ones and asks Emma to sacrifice him with Excalibur, saving everyone and returning Emma to normal . Emma discovers Gold used the situation to tether the darkness back into himself, leading Emma to blackmail Gold into helping her bring Hook back from the Underworld . Meanwhile, Regina sends Zelena back to Oz, after Zelena attempted to get sole custody of her daughter . </Td> </Tr> <Tr> <Th> 100 </Th> <Td> 12 </Td> <Td> "Souls of the Departed" </Td> <Td> Ralph Hemecker </Td> <Td> Edward Kitsis & Adam Horowitz </Td> <Td> March 6, 2016 (2016 - 03 - 06) </Td> <Td> 4.01 </Td> </Tr> <Tr> <Td_colspan="7"> The heroes arrive in the Underworld, which bears a striking resemblance to Storybrooke . Here, souls with unfinished business live, including Peter Pan and Cora . Cora offers Regina a way out, telling her she has one hour to leave on the ferry with Henry and Robin . Regina finds the soul of her father, whom Cora has threatened to send to a deeper layer of hell if she does not leave soon . When Regina's father tells her she has come too far to betray her friends now, Cora attempts to banish him . However, as Regina has chosen to stay, Cora's attempts are ineffective, as seeing his daughter choose to stay a hero resolved his unfinished business . With his soul at peace, he is accepted into "a better place" and departs the Underworld after saying goodbye to Regina and Henry . The heroes realize they could potentially rescue all the souls here and continue their quest to find Hook with this in mind . Cora meets with the ruler of the Underworld, Hades, who wishes the heroes gone . He punishes Cora for her failure with an eternity as a miller's daughter once again . Flashbacks show Regina celebrating her birthday with a surprising visit from her mother, Cora . </Td> </Tr> <Tr> <Th> 101 </Th> <Td> 13 </Td> <Td> "Labor of Love" </Td> <Td> Billy Gierhart </Td> <Td> Andrew Chambliss & Dana Horgan </Td> <Td> March 13, 2016 (2016 - 03 - 13) </Td> <Td> 4.31 </Td> </Tr>

Whats the last season of once upon a time