When anarchists slash a painting of the Prime Minister in the newly opened National Portrait Gallery and suggest that the man himself could be next, Scotland Yard have no choice but to call in Sherlock Holmes. Leaving Watson behind, Holmes fakes his own death, infiltrates the anarchists, and solves the problem – only to return to Baker Street and discover that his problems are only just beginning.  
Forged paintings, exotic criminal gangs and threats to the monarch are only the start as Holmes and Watson criss-cross London and southern England, in pursuit of the solution to a centuries-old puzzle. As the mysterious master criminal The Albino closes in on them, Holmes and Watson find themselves in a race to unravel the clues and locate England’s long-lost treasure!