Desmond Drake is an agent with British Intelligence.
He is officially attached to the Foreign Office, Special Duties Department, performing highly covert missions while telling his friends in his usual friendly and verbose way that he is on vacation.
The three-book series recounts the adventures of Drake in the service of the Crown. The first mission took place during the Second World War while Drake was in the Royal Navy, working with the Intelligence division there. To hear Drake describe it, it was six long years of sitting on the seat of his pants waiting for something to happen, with one interesting exception. That exception was the affair detailed in the first book, helping to destroy a German battleship. For his actions, he was awarded the Distinguished Service Cross.
The remaining books take place after the War while Drake is with the SDD. He might describe his times away from London and his apartment as vacations but the author states that others would more aptly call it “skullduggery”. Drake might laugh with pleasure at that description but he would probably not argue too strongly.
In the first adventure, Drake is depicted as “dark of hair and eye, blue-jowled, broad-shouldered and muscular”. He is also reported to be a tall man with long legs which he is prone to drape over chair arms. Drake seldom sits in a chair, he lounges in it, possessing an air of good-nature amusement at what the world throws at him. He most decidedly enjoys actions and gets terribly bored easily without it.
Drake has an arch-nemesis who plagues him in all three adventures, a German agent named Hermann Vogel. This highly capable agent works for the German High Command during WWII and becomes an East German operative after the war. He has considerable respect and hatred for Drake, a combination of feelings definitely returned.