The Mask of Dimitrios by Eric Ambler

A crime novelist has found the perfect subject - but it may cost him his life 

English writer Charles Latimer is travelling in Istanbul when a police inspector tells him about the infamous master criminal Dimitrios, long wanted by the law, whose body has just been fished out of the Bosphorus. Immediately fascinated, Latimer decides to retrace Dimitrios' steps across Europe to gather material for a new book, but instead finds himself descending into a terrifying underworld of international espionage, Balkan drug dealers, unscrupulous businessmen and fatal treachery - one he may not be able to escape.