Marque and Reprisal is the second volume of Elizabeth Moon’s latest series, Vatta’s War. Like much of her fiction, these books have action/adventure plots; and as is typical of Moon’s writing in this mode, their protagonist is a woman. But unlike Moon’s previous adventure heroines—Paksenarrion, Heris Serrano, and Esmay Suiza—Kylara Vatta is not in military service; she’s the captain of a merchant starship. And the focus of these books is much less on military organizations, and much more on commercial ones.

By and large, Moon offers a positive view of business organizations. Three business firms play a major part in these books: Vatta Transport Ltd., the interstellar shipping firm run by Kylara Vatta’s family; InterStellar Communications, an immensely powerful firm that holds a monopoly on instantaneous communications; and Mackensee Military Assistance Corporation, a mercenary force in whose operations Vatta repeatedly finds herself entangled. All three are basically ethical organizations, earning their profits by selling their services on honest terms, and concerned with long-term advantage more than quick gain. On the other side of things, Moon shows Vatta’s need to deal with government failures, from simple bureaucratic obstructiveness to the deliberate refusal of the government of her home planet, Slotter Key, to protect Vatta Transport from physical attack on its people and facilities.

At the same time, Moon establishes that Vatta is not, by first choice, a merchant at all. The first book in the series, Trading in Danger, began with her expulsion from the naval academy of Slotter Key, in disgrace, after she unwisely offers help to a classmate with a personal problem. Her merchant captaincy is on an old, small ship, carrying one last cargo on its voyage to be scrapped, as a way for her to prove herself to her family. Her adventures come about when plot complications involve her in problems where her military education is more help than her mercantile abilities.

What Moon is doing with this series is exploring the relationship between two distinct sets of ethical values, identified by Jane Jacobs in her book Systems of Survival: the guardian ethos and the trader ethos, embodied respectively in the soldier and the merchant. Moon is ingenious in dramatizing the tension between them—in Kylara’s background, in her feelings about the actions she has to perform, and in the relationship between military and commercial institutions. The book’s very title points at that conflict: letters of marque and reprisal are a way of applying mercantile methods to the very nonmercantile business of warfare—and Moon’s narrative shows that, as Jacobs describes, the intermixture of the two has the potential to corrupt both, if not handled with the utmost care. There are serious themes, and themes of interest to libertarian audiences, underlying this story of heroic action and conflict between the stars.