Frank Bowen is an agent with MI-6.
Not when we first meet him, though. Then he is a man in need of a break, ready to end his long relationship with his girl friend whom he did not like much anymore nor she him. He receives a small inheritance from his grandfather and then witnesses a traumatic event and decides a change was definitely in order. He says goodbye to the lady and lets his buddy, Carl, know, and off he headed to far sunnier and warmer climes than London.
That will eventually land him in the thick of a mess he had had no way of knowing he would find himself, meeting a lovely lady in a foreign land, getting chased by people who want him killed for reasons he might not have believed possible, and then ending up back home with a new family and a new job. That job would be with Carl who, Bowen had known for years, was with MI-6.
Bowen is in his late 20's when we meet him and a man who has to work hard to try to stay in some decent sort of shape. He is usually neither happy nor sad but largely just seems to go along which may be why he gets into the troubles he does.
This series of adventures is named the Frank Bowen Conspiracy Thrillers for a reason. Bowen is a straight-forward sort of fellow, not especially ambitious (okay, to be honest, not hardly at all), who does not see conspiracies in every action around him. They just sort of see him coming, though, and pull him in. Bowen is sharp enough to see them coming but not limber enough to get out of the way. Luckily, he is good enough, or luckily enough, to survive their advances.