Snow & Charming Argue Over Lancelot In Once Upon a Time Clip From The Broken Kingdom

ABC has released a new sneak peek from this Sunday's episode of Once Upon A Time: "The Broken Kingdom."

The darkness has taken its toll on poor Emma (Jennifer Morrison) and her concerned parents can't agree on the best course of action to make her well. Charming (Josh Dallas) wants to bring Emma's enchanted dagger to Arthur, but Snow (Ginnifer Goodwin) doesn't want to do that because she was informed by Lancelot that Arthur can't be trusted.

Check out the clip in the video below.

After receiving a cryptic warning from Lancelot about Arthur’s intentions, Mary Margaret realizes Arthur may be the heroes’ biggest threat, but when she is unable to convince David of the danger, she takes matters into her own hands. Meanwhile, Hook’s unwavering love for Emma provides a glimmer of hope in her struggle against the unrelenting voice of Rumplestiltskin. In a Camelot flashback, Guinevere senses that Arthur is losing his way, consumed by his obsession with making Excalibur whole, so she sets out with Lancelot on her own quest into the heart of darkness. In Storybrooke, Dark Emma unleashes a secret weapon in the next phase of her plan to find the brave soul she needs to draw Excalibur from the stone.

"The Broken Kingdom" episode of Once Upon A Time airs Sunday, October 18th at 8/7c on ABC.