The next episode of "Once Upon a Time" will not be aired until the second week of April, but new images show what fans should look out for in the next installments of the hit fantasy drama from ABC. 

Based on the images posted by TV Line, Robin Hood (Sean Maguire) faces the Wicked Witch of the West (Rebecca Mader) in flashbacks when he had to steal a very important magical elixir upon the orders of Rumplestiltskin (Robert Carlyle). But will the green-colored baddie remain in the past, or will she manage to return to the present day Storybrooke? 

The official synopsis for the episode reads: 

"Emma is still reeling after learning the truth of her parents' history with Maleficent, but she must focus on finding the Author, who is running loose in Storybrooke, before Gold does. When Gold's quest for his happy ending grows more urgent, he blackmails Regina into helping him. In a Fairy Tale Land flashback, Robin Hood learns what it means to be an honorable thief when he accepts a proposition by Rumpelstiltskin to travel to Oz to steal a valuable magic elixir from the Wicked Witch." 

Meanwhile, all the efforts made by Snow White (Ginnifer Goodwin) and Prince Charming (Josh Dallas), as well as their friends, to protect their daughter Emma Swan (Jennifer Morrison) might end up in vain. Speculations claim that Emma might turn to the dark side after learning the truth about her parents. 

Actor Colin O'Donaghue, who portrays the role of Captain Hook in the series, teased about Emma's struggles in the remaining episodes of "Once Upon a Time" season 4 during an interview with TV Line. The actor said that the second half of "OUAT" season 4 deals with the struggles that both the heroes and the villains have to deal within themselves.

"They've all done something that they regret, but learn from it in a positive way. We've seen moments where you could see where Emma could maybe become darker. Whether or not she does is a whole other thing," O'Donoghue said.

"Once Upon a Time" season 4 returns on April 12.