Emma Swan (Jennifer Morrison) will continue to grieve over the absence of Captain Hook (Colin O'Donoghue) in episode 15 of "Once upon a Time" season 6.

The official synopsis for the upcoming episode titled "A Wondrous Place" reveals that Hook will continue to be trapped in a different world with Nautilus crew.

Previously, the lovers had a misunderstanding. Emma found out that Hook was the person behind the murder of his grandfather and got angry when he did not tell her about it. On the other hand, Hook explained that he kept it as a secret because he was uncertain whether Emma would understand it or not. In the end, Emma felt sad, believing that Hook still had trust issues in their relationship.

Without having the chance to fully mend the matter, Gideon (Giles Matthey) kidnapped Hook. He hijacked the ship of Captain Nemo (Faran Tahir) and tricked the pirate to go with them. Before Hook realized what was going on, the ship had already gone below the sea.

In the promotional preview of episode 15, Hook is clearly frustrated with his situation as he tries to find ways to escape. Emma is also in despair as she holds on to her engagement ring, thinking that Hook may have completely abandoned her. Meanwhile, Snow White (Ginnifer Goodwin) and the Evil Queen (Lana Parrilla) are both clueless on how to console her.

The teaser also reveals that Aladdin (Deniz Akdeniz), Jasmine (Karen David), and Ariel (JoAnna Garcia Swisher) are with Hook in the vessel. It is still unclear how they got there, but in the latter part of the clip, Jasmine tries to stop Hook from trying to escape. Are they accomplices of Gideon?

Still, Hook is determined. He tells them, "Every moment that I stay here is killing me."

Episode 15 of season 6 airs on Sunday, April 2, at 8 p.m. EDT on ABC.