When a fleeing Sam Wiggins runs into Sherlock Holmes one day, Sam never imagines that he will become a detective himself, helping Sherlock Holmes as well as working with the other members of the Baker Street Irregulars - Billy, Potts, Titch and Edie - to solve mysteries on their own. In The Dragon Tattoo, a Chinese friend of Sam's is kidnapped ... Sherlock Holmes has disappeared. Billy Chizzell dreams of hitting the headlines: YOUNG HERO LOCATES MASTER DETECTIVE! Billy's search takes him to Limehouse and an encounter with evil. Rescued by Sam Wiggins, Billy agrees to help Sam.