Sherlock Holmes and Dr. Watson help an old friend search for a missing family member. Weeks later, Inspector Lestrade calls them to a suspicious death. Finally, a telegram summons the pair to Paris. These three seemingly unrelated incidents lead the detective to uncover an international mystery that stretches across the borders of three countries, dominated by deception and death.

Holmes and Watson join forces with the Paris police to investigate a series of arson fires and three deaths that lead them to murder. As they uncover the clues that will eventually point them back to London, they themselves become the targets of murder in an attempt to stop their investigation.

As the investigation moves back to London, the attempts on their lives continue. Finally, a dangerous trap is set, and with the help of Mycroft and Inspector Lestrade of Scotland Yard, Holmes and Watson force their quarry to show their hand. Can the international conspiracy be thwarted? Can the criminals be brought to justice? What will be the final cost in lives? Join Holmes and Watson as they fight to bring justice to an international ring of thieves and the mastermind behind them.