‘Once Upon A Time’ Season 6 Spoilers: King George Returning To Terrorize Snow & Charming; Evil Queen Prepares To Destroy Storybrooke

Prince Charming (Josh Dallas) and Snow White (Ginnifer Goodwin) will face a menacing blast from the past on "Once Upon a Time" Season 6. Alan Dale is reprising his role as the villainous King George in the ABC series.

King George, who first appeared on "Once Upon a Time" Season 1, made a deal with Rumplestiltskin (Robert Carlyle) to get an heir because his wife can't bear children. That heir was James, whose sudden death spurred King George to find his twin David, who is also portrayed by Dallas.

David took his twin brother's place in the kingdom, got betrothed to King Midas' (Alex Zahara) daughter Abigail (Anastasia Griffith), but ran away to be with Snow. This rebellion incited David and King George's animosity towards each other and the latter vowed to make David's life with Snow a living hell.

"Once Upon a Time" creators Edward Kitsis and Adam Horowitz told Entertainment Weekly that King George will "cause trouble for Snow and Charming in an episode later this season that shines a new light on all of their pasts and has a profound impact on their futures." David, meanwhile, is currently busy trying to uncover the truth behind his real father's death.

David suspects that there's more behind the man's drunken cart accident. Aside from these, David and Snow are trying to help Emma (Jennifer Morrison) topple her prophesied death in the hands of a hooded man, according to TVGuide.

Episode seven of "Once Upon a Time" Season 6 titled "Heartless" will showcase the Evil Queen (Lana Parrilla) threatening to destroy Storybrooke unless David and Snow give their hearts to her. Emma, Hook (Colin O'Donoghue), and Henry (Jared S. Gilmore) will do what it takes to stop the Evil Queen as David, Snow, and Regina look for "a magical sapling created by the first spark of true love," SpoilerTV reported.

Regina will also use Mr. Gold's and the Evil Queen's budding romance against them on "Once Upon a Time." Belle (Emilie de Ravin) will receive a friendly advice from Zelena (Rebecca Mader).

The teaser for the upcoming Once Upon a Time" episode also showcased a bottle filled with a magical substance that can destroy Storybrooke. The "Once Upon a Time" characters were shown sitting in a room contemplating about the actions they'll do next, with Regina saying that they only have 12 hours to "figure it out."

"Once Upon a Time" episode seven airs on Sunday, Nov. 6 (8:00-9:00 p.m. EST) on ABC. Watch the promo below.