Guy Ritchie's Young Sherlock is now streaming on Prime Video, bringing his signature kinetic style to a 19-year-old version of the detective. But despite Ritchie directing the series, it is completely disconnected from Robert Downey Jr.'s stalled Sherlock Holmes 3 movie. Young Sherlock is an eight-episode Amazon original series starring Hero Fiennes Tiffin as a teenage Sherlock Holmes. The show is based on Andy Lane's young adult novels and serves as a standalone origin story