'Once Upon A Time' fans rejoice! Season 4 episode 18 titled "Heart of Gold" is set to air this Sunday night and things are looking great for everyone until a villainous character returns. Elsewhere, Robin Hood is also returning but he will be in two different lands, without any illusions whatsoever. Don't miss the exciting episode tonight. Tune in on ABC at 8 p.m. EST or simply watch 'Once Upon A Time' season 4 episode 18 stream using the free online stream link below.

Note: This feature contains spoilers on the upcoming episode of 'Once Upon A Time' Season 4. Kindly read at your own risk.

Previously on 'OUAT,' Emma is being tricked into the darkness by Gold while secrets continue to surface, including Mary Margaret and David's past with Maleficent. Emma then realizes that her only childhood friend, Lily, is Maleficent's daughter. This week, Zelena returns to Storybrooke only to wreak havoc among its inhabitants. Who is she after and what is she up to? Spoilers hint that she's visiting Gold in his hospital room. Could this mean the end for Gold? Find out all of the answers by watching 'Once Upon A Time' season 4 episode 18 online using the free online stream link at the bottom.

Additionally, fans will see the return of Cruella de Vil in the upcoming 19th episode of the series. When the three evil characters got introduced in the mid-season premiere of season 4, somehow fans wanted them to get their own happy endings. The April 19 episode will cover Cruella's fate. But before that Show co-creator Eddy Kitsis has dished that a big revelation is up for tonight's show. "It is going to be revealed Sunday night and like all good villains, they take what you love and use it against you," Kitsis told TVLine. Watch 'Once Upon A Time' season 4 episode 18 stream using the free online stream link at the end of this post.

The official synopsis of 'Once Upon A Time' season 4 episode 18 reads: "Emma is going to still be reeling after learning the truth of her parents' history with Maleficent, but she is going to have to focus on finding the Author, who is running loose in Storybrooke, before Gold does."

Another synopsis goes something like this: "Gold blackmails Regina into helping him locate the Author before a determined Emma does. Meanwhile, back in fairy-tale land, Robin Hood accepts a job from Rumpelstiltskin and heads to Oz to snatch a prized potion from the Wicked Witch of the West."

"Heart of Gold" is set to air this Sunday evening on ABC at 8 p.m. EST. Watch 'Once Upon A Time' season 4 episode 18 stream using the free online stream link here.