In Poor Unfortunate Soul (the fifteenth episode of the fourth season of  Once Upon a Time) people interrogate adult August Booth who says he stole for a man named The Dragon.
"Poor Unfortunate Soul" is the fifteenth episode of the fourth season of the American fantasy drama series Once Upon a Time, which aired on March 22, 2015. At Gold's remote cabin, Regina, Maleficent, Cruella, and Ursula start interrogating adult August Booth about the Author. He explains that he stole the research of a man in Hong Kong named The Dragon, and that the research is still currently in Storybrooke. 
