Season 5 of “Once Upon a Time” continues Sunday night on ABC with episode 3, “Siege Perilous.” Fans will once again revisit Camelot to put the pieces together to find out what happened to Emma (Jennifer Morrison) to turn her into the Dark Swan. The mystery will unravel in Storybrooke … as Emma works to free Excalibur from the stone.

Watch three sneak peek videos from episode 3 before “Siege Perilous” airs:

Sneak Peek #1

Now that Rumpelstiltskin (Robert Carlyle) is reappearing as a figment of her imagination again, Emma is on an evil path to reuniting the Dark One’s dagger with Excalibur. Episode 2 showed that she no longer has the power of the Savior to pull Excalibur from the stone. So, how’s an evil person to get their hands on a powerful sword? A dwarf axe!

A dwarf axe is supposed to cut through everything … but unfortunately not magic. When Emma fails with the axe, Rumpelstiltskin suggests she gets her hands on a hero. But who is the hero?

Sneak Peek #2

Hook (Colin O’Donoghue) better watch out because Emma wants something from him. The Dark One visits her estranged beau on the Jolly Roger, and Hook is surprised to see her … especially since last time she called him out for failing to “fix” her with true love’s kiss.

Emma apologizes to him, but Hook isn’t buying it. That’s when Emma uses her magic to sway him into hanging out “like old times.” Will Hook fall into Emma’s trap and trust her? Or will he see through her?

Sneak Peek #3

This sneak peek video brings viewers back to Camelot before Emma turned dark. However, one person is showing their evil side … Regina (Lana Parilla).

In an effort to keep their secret about the Dark One in Storybrooke, Regina uses magic to mute Zelena (Rebecca Mader) and forces her to be her hand maiden. But that’s not Regina’s real punishment for her evil half-sister. Although Zelena insists that all she wants is a chance to get things right with her baby, Regina warns her that that’s not going to happen.

“Once Upon a Time” Season 5, episode 3 will air on ABC on Sunday, Oct. 11 at 8 p.m. ET. What are you looking forward to watching unfold? Tweet your thoughts to @AmandaTVScoop.