The new series, featuring a cast of fresh talent, is loosely based on the concept of the Baker Street Irregulars from Arthur Conan Doyle's Sherlock Holmes stories, in which street tuffs help the famous detective solve mysteries by getting him information. (They're originally kind of like Lord Varys' little birds in Game of Thrones.) The show, however, has a supernatural twist and lots of dramatic secrets to uncover as the teenagers get deeper and deeper into Holmes' world. A few other characters from the Conan Doyle canon, like Sherlock's brother Mycroft Holmes, the bumbling Inspector Lestrade, and the landlady Mrs. Hudson. But at the end of the day, this is a show about five teenagers living in the London society that Holmes and Watson are trying to protect.
About half of the cast members were pulled from the Netflix well, meaning they already have credits on the streaming service's original series or films. But not all of them. Some are known outside of Netflix, and some are breaking out in this series.