'Once Upon a Time' season 6 episode 3 spoilers, promo trailer & updates: Series tackles Cinderella story as Prince Charming sets out on quest

When "Once Upon a Time" season 6 returns for its third episode on Sunday, David will be on a quest to learn more about his father as Ashley tries to settle the unfinished business between her and her step-family.

In episode 2 titled "A Bitter Draught," Storybrooke's townsfolk continued welcoming the refugees from the Land of Untold Stories. Regina (Lara Parrilla) tried her best to pacify the crew and tell them they have nothing to be scared of since she is a good person already and will be ready to help them. The Count of Monte Cristo (Craig Horner) also made his presence felt, although Regina warns David/Prince Charming (Josh Dallas) and Snow (Ginnifer Goodwin) that the Count is there to kill them.

Apparently, Regina knows because she was the one who hired Edmond Dantès a.k.a. The Count of Monte Cristo when the Evil Queen was still residing in her. It was a simple exchange of deal, the Queen will give him a list of people he needs to hunt for his bad run of fortune in exchange for him killing the Charmings since she is unable to harm them herself.

Meanwhile, a battle ensues between the Count and the Charmings, with Regina finding out that the Evil Queen has been in control of the Count through his plucked heart. Ultimately, Regina ended up killing the Count, after which her evil counterpart revealed that the plan was never for the Count to kill the Charmings but for Regina to kill the Count so that a bit of darkness will once again grow inside her.

Sunday's episode titled "The Other Shoe" will find Ashley/Cinderella (Jessy Schram) searching for her step-family in an effort to settle their unfinished business. Emma and Hook (Colin O'Donoghue) will help her to make sure she does what she intends to do before it's too late. A flashback scene will also show Cinderella attending a ball and meeting her prince.

On the other hand, Regina will try to bribe Mr. Hyde (Sam Witwer) for information on how she could defeat the Evil Queen while Snow helps Dr. Jekyll (Hank Harris) find a laboratory for his work. In the meantime, David will be on a mission to find out more about his family, something that will give fans a glimpse into his backstory. He will strike a deal with Mr. Gold/Rumplestiltskin (Robert Carlyle), delivering a message to Belle (Emilie de Ravin) in exchange for the information he needs.

"Once Upon a Time" season 6 episode 3 will air on Sunday, Oct. 9, 8 p.m. on ABC.