Based on Arthur Conan Doyle's Sherlock Holmes, The Baker Street Four provides an inside look behind the infamous Baker Street Irregulars. Billy, Charlie, and Tom are inseparable, and for good reason. Filled with con men and scoundrels, London's East End is not a place that is easily survived alone. Fortunately, these three boys can count on the protection of Sherlock Holmes, for whom they sometimes act as spies. When Tom's girlfriend is kidnapped, the heroes will have to use their budding sleuthing skills to find her. Along the way, they unexpectedly add a fourth member to the team and ultimately become the youngest detectives of the Victorian era.