Sir Alfred Connyngham gets clobbered while defending a woman in the street and loses an dispatch case that contains vital documents. The Baker Street gang suspects the attacker and the woman were working together.
Sparrow has overheard two foreign spies planning to bomb an Archduke, but needs help from the rest of the gang figuring out what it all meant and where it will take place.
Holmes has the Flu and Lestrade thinks Charley Telfer is behind the recent Midwinter murder. Wiggins decides the Baker Street Boys will solve the murder and clear Charley's name.
Professor Moriarty announces to Doctor Watson that he has kidnapped Sherlock Holmes to stop him thwarting his plans. Rosie and Queenie overhear and Wiggins come up with a scheme to help Mr. Holmes.
Wiggins and Beaver inform Moriarty that they have stolen the Winged Scarab before him and want to trade it for Sherlock Holmes. Moriarty agrees to a swap, but Lestrade is hot on the Baker Street boy's trail.
Sparrow helps a young American girl flee from her stepfather and his mind reading act. For the next performance, Queenie is hired to replace her on stage.
Following a murder at the theater, Queenie has been kidnapped. The Baker Street Boys team up with a Pinkerton man to catch some members of the notorious Iron Fist Gang.