Mrs Hudson must step into action once more. It's summer in London, and things are quiet. But while Sherlock Holmes and Dr. Watson chafe at their inactivity, a train carrying a vital secret is entering a tunnel in an obscure region of the Balkans - never to be seen again. The train is only the beginning. The missing message must be found and decoded, and a diplomat's wife must be rescued from the clutches of a pernicious blackmailer. The nation is in danger, and if a diplomatic scandal of disastrous proportions is to be avoided, Sherlock Holmes' brilliance may not be enough ... Mrs Hudson and Flottie her assistant will once again turn detective. From the Richard and Judy-featured author of The Conjuror's Bird , back by popular demand, the first new Holmes and Hudson novel for several years.