Book excerpt: Hector C. Bywater was perhaps the British secret service's finest agent operating in Germany before the First World War, tasked with collecting intelligence on naval installations. Recruited by Mansfield Cumming, the first 'C' (or head of what would become MI6), Bywater was given the designation 'H2O' in what was a rather obvious play on his name - and the equivalent of James Bond's '007'. Indeed, the charming, courageous Bywater probably came as close to the popular image of Ian Fleming's most famous character as any British secret agent ever did. Originally written up in 1930 as a series of thrilling articles in the Daily Telegraph, his experiences were soon turned into a book, with the help of Daily Express journalist H. C. Ferraby, collating Bywater's espionage endeavours in one rollicking tale of secret service adventure. Although the identities of the British spies carrying out the missions in Strange Intelligence are disguised, we now know that most of them were in fact Bywater himself. Ahead of a war that was to put the British Navy to its sternest test since Trafalgar, Bywater reveals how he and his fellow agents deceived the enemy to gather vital intelligence on German naval capabilities. His account is a true classic of espionage and derring-do.