The Sign of Four (Paperback) (ISBN-13: 9780140439076)

Arthur Conan Doyle (1859-1930) was born in Edinburgh and took a degree in medicine at Edinburgh University before becoming a doctor in Southsea. He began writing detective stories to supplement his income and 'A Study in Scarlet' (1887) introduced his finest creation, the hawk-eyed detective, Sherlock Holmes.

Peter Ackroyd is a well known writer and historian. He has been the literary editor of The Spectator and chief book reviewer for the The Times, as well as writing several highly acclaimed books including a biography of Dickens and London: The Biography. He resides in London and his most recent highly acclaimed work is Thames: Sacred River.