Young Sherlock: Everything we know about cast, plot and production team of Amazon series

Colin Firth joins Amazon's "Young Sherlock" series, inspired by Andy Lane's novels. Hero Fiennes Tiffin leads as young Sherlock Holmes. Firth will play Sir Bucephalus Hodge. The show is about a 19-year-old Sherlock solving a murder mystery at Oxford University. Matthew Parkhill writes and executive produces, with Guy Ritchie directing.