The heroes of Storybrooke will be forced to work with unexpected allies on the next episode of "Once Upon a Time" season 6.

Based on the synopsis that was released by ABC, both Gold (Robert Carlyle) and Belle (Emile De Ravin) will try to persuade Emma (Jennifer Morrison) to work with their son Gideon (Giles Matthey) to stop all the evil plans of the Black Fairy (Jaime Murray).

However, the trailer reveals that Emma will be reluctant to help Gideon since he is very determined to kill her. But Gold will remind her and Snow White (Ginnifer Goodwin) that all the darkness that they have encountered were born from one soul, who happens to be the Black Fairy. This could possibly influence Emma to try to trust Gideon in order to end the Black Fairy's plans.

In one of the scenes in the trailer, both Emma and Gideon will be attacked by a giant spider. Emma asks Gideon how they will defeat the monster, but Gideon reminds her that she is the Savior, so she should think of the best way to help them survive.

The synopsis also reveals that Henry (Jared S. Gilmore) will encounter a confusing change in his powers. This will prompt his adoptive mother Regina (Lana Parrilla) to look for answers from the previous Author (Isaac Heller) to help Henry deal with the changes that he experiences.

On the other hand, Hook (Colin O'Donoghue) will try to get into the good side of his old nemesis by betting his most important possession on a card game. The synopsis also reveals that the episode will feature a flashback where the Black Fairy is seen torturing the young Gideon in her quest to make him her perfect apprentice.

ABC will air the next episode of "Once Upon a Time" season 6 on Sunday, April 9, at 8 p.m. EDT.