By the Sword is told almost entirely in Kerowyn's point of view and voice, a technique that strengthens the novel's intensity compared to most of the author's works. It is divided into three separate "books" within one volume.

The first, "Kerowyn's Ride," follows Kerowyn through her heroic ride and her arms training under Tarma, ending with her decision to seek entrance into the Skybolts, a bonded mercenary company. "Two Edged Blade" deals with her life as a member of this troop. "The Price of Command" picks up ten years later, after she has served as the Skybolts' captain for a decade, rebuilding the company after its near-destruction under a feckless former captain. The third book ends with a rush of new events. The Skybolts enter Valdemar, a land which previously disdained mercenaries, to help repel an invasion.

There is a big battle with a desperate last-minute charge; Kero's...