London is quiet, too quiet, and Holmes and Watson chafe at their inactivity. Then comes alarming news from the Balkans: a train carrying a vital coded message entered a tunnel – and never reappeared. The vanishing train and missing message mean Holmes and Watson confront a growing national crisis, but the investigation soon demands the talents of those below stairs at Baker Street, and in steps Mrs Hudson and her trusted assistant Flotsam. The solution to a diplomatic disaster and the fate of nations rests in the hands of Sherlock Holmes’s remarkable housekeeper. A fresh twist on Conan Doyle’s timeless world, Holmes & Hudson uncovers the hidden stories behind Baker Street’s famous door.