Peter Cotton is an agent with British Intelligence.
The Second World War is nearing an end as the series opens though hostilities are still extremely high as one side senses victory and the other worries about its fate. A relatively young man, at least in years if not in experience, Cotton has been moved from the military, where he had held the rank of Captain in the British Army, to the Intelligence field. Further, he has been sent into the field where he must operate alone with only his wits to keep him alive.
Though Cotton is a British citizen, life in Europe is viewed from a different vantage point as he had been raised mostly in South America where his father had a job. As a result of his upbringing, he speaks Spanish like a native although it is far more gutteral dialect from the streets southern and western hemisphere than is spoken in Spain. His first solo assignment, chronicled in the first book, finds that out.
At 25 years old, Cotton is a bit shy at times, or at least that is how he appears. He is tall, standing 6'1", having fair hair and blue eyes. His relative youth, when posed against people considerably older and more experienced, makes him look naive and untested. His years in combat before he came to the Intelligence field, though, show a different story.
Cotton is single but bears the scars of an engagement that ended with the death of his fiancee in an air raid earlier in the war. While he appreciates the beauty of ladies he meets, he still remembers what he lost. He is respectful to ladies and does not press his attentions but he is not a shrinking violet and he is not at all shy.
As the series progresses, so does the learning by Cotton. His rank in the military he is only nominally a part of increases and his responsibilities in the Intelligence community grows as well.
The series takes place during the last days of WWII and the period after the global conflict, though it is written very recently. The author has managed to capture a great deal of the atmosphere from that period and even has the feel and vibe of a series actually penned back then. There is action but it is often subdued, not exploitative. There is far more mystery and day-to-day life in these pages than bouts of explosion and mayhem. The mayhem does go on, however, and it jumps up to bite you just when you think the case is winding down.