The book presents a kind of fictional biography of a mild-mannered young man, who likes and excels at all kinds of sporting combat. The idea of using his exceptional talent anywhere outside a sporting arena is anathema to him, but because of various circumstances that he encounters along the way and a strong dislike of bullies and criminals of all kinds, he gradually discovers a darker side to his nature. In due course, this is harnessed by forces of law and order to help them achieve their purpose, without knowing too much or indeed caring too much about how he goes about it.
It is perhaps surprising how two separate love affairs affect the directions he takes.