"There - is - danger!" The warning message decrypted by Sherlock Holmes arrives too late to save John Douglas of Birlstone Manor, Sussex, an American gentleman gruesomely murdered in his study by person or persons unknown. But who was John Douglas, why wasn't he wearing his wedding-ring, and what is the crucial significance of the missing dumb-bell?

This atmospheric graphic novel adaptation by Ian Edginton and I.N.J. Culbard - the team behind this series' acclaimed A Study in Scarlet, The Hound of the Baskervilles and The Sign of the Four - will keep you guessing.