The Fourth Doctor and Leela arrived on a planet with the usual lack of control and, leaving the TARDIS, the pair made their way into the outside world. Once past the obligatory unobtrusive corridor they find themselves in an arena and when they are confronted by a security guard. For some bizarre reason, he challenged the Doctor to a duel, though he rapidly went off the idea when Leela hit him.
But the Doctor and Leela are the ones who found themselves in jail, apparently for the crime for refusing to kill the downed guard.
This is quite a fun book in a way, giving us a look at a Doctor confused at multiple levels; he could never get his head round the reasoning behind the duelling code and the strange dichotomy it enforced on the legal system. He had a plan to find out what was going on but it depended on Leela's unwillingness to kill for sport and she was being seduced by the surrounding atmosphere. Rather unusully, the Doctor never really gets a handle on the situation and he found himself in the role of the one being used rather than the one using others.
Another strand of the story follows Keefer as he attempts to find out who has declared open season on his own life. Keefer is an accomplished duelist and he might live long enough to find out who wanted him dead but would he like the answers.