'Once Upon A Time' Season 3 Premiere: Emma And Hook Share A Moment In 'Heart Of The Truest Believer' (EXCLUSIVE VIDEO)

Are you ready to venture into Neverland, dearies? "Once Upon a Time" Season 3 debuts on September 29 (8 p.m. ET on ABC), and HuffPost TV has an exclusive first look at the premiere, titled "Heart Of The Truest Believer."

We last saw our favorite heroes -- and villains -- headed off in search of Henry (Jared Gilmore) on the Jolly Roger, and as you might expect, being trapped at sea with your nemesis doesn't make for a particularly enjoyable summer vacation. Our exclusive preview sees Emma (Jennifer Morrison) working out some of her frustration, but it's not long until Captain Hook (Colin O'Donoghue) seeks her out for some teasing banter -- and a surprisingly heartfelt revelation.

Fans have a lot to look forward to this season on "Once" -- we'll finally meet Ariel (JoAnna Garcia Swisher) and Prince Eric (Gil McKinney), as well as Tinkerbell (Rose McIver) and a wholly unique version of Peter Pan. The inimitable Giancarlo Esposito will also be making a return visit as the Magic Mirror, while Robin Hood will be back in the form of Sean Maguire.

Watch our preview of "Heart of the Truest Believer" above, and check out an episode description and photos from the premiere below.

"Heart of the Truest Believer" -- As Emma, Mary Margaret, David, Regina, Mr. Gold and Hook enter Neverland to search for a kidnapped Henry, they're greeted by a school of not-so-friendly mermaids who threaten to end their search before it begins; Henry finds himself on the run from the Lost Boys with another escapee from Peter Pan's encampment; and Neal, recovering from his wounds, travels through the Enchanted Forest with Mulan in an attempt to learn the fates of Emma and Henry.

"Once Upon a Time" Season 3 premieres Sunday, Sept. 29 at 8 p.m. ET on ABC. Its spinoff, "Once Upon a Time in Wonderland" premieres Thursday, Oct. 10 at 8 p.m. ET on ABC.

Once Upon a Time