Emma is meeting another person who believes in fairytale when "Once Upon a Time" returns with a new episode. While searching for a missing Mary Margaret, Emma is kidnapped by a guy whose affinity for hats has him teetering on the edge of madness. Played by Sebastian Stan, the man thinks he is the Mad Hatter of "Alice in Wonderland".
Meanwhile, viewers will be transported outside the fairytale land that was for the first time when the Evil Queen persuades a skillful man of magic to come work for her one last time and travel to Wonderland in order to help steal something from the Queen of Hearts.
"Hat Trick", which will also feature Roger Daltrey as a guest star, will air Sunday, March 25 at 8/7c on ABC. Executive producer Edward Kitsis previously said, "In that episode, we find out how the Mad Hatter became mad."
The episode will also have a twist to "Alice in Wonderland" tale. "The first difference you'll notice is who the Mad Hatter was and his backstory," Kitsis shared. "Then what Wonderland is and the changes of it is something we hope to explore also. We're hoping this tells you the story of the Mad Hatter, but also will leave you with questions about Wonderland."