Clive Merrison and Andrew Sachs star in three brand new BBC Radio 4 full-cast adventures. How many times did Dr John Watson tantalise us with a passing reference to a mystery that his creator, Sir Arthur Conan Doyle, never wrote about in full? In these full-cast original adventures, Bert Coules, the chief dramatist of BBC Radio 4's celebrated complete Sherlock Holmes canon, has imaginatively fleshed out three such unrecorded cases.