In a bustling, fairy-tale city, the aristocrats live on the Hill, while the poorest, and the criminal element, live in Riverside. Richard St. Vier is a swordsman living in Riverside with his lover, Alec. Richard makes his living fighting duels for the honor of various aristocratic houses, in an archaic system of challenges and champions.

Everyone is gossiping about Lord Horn's garden party, where Richard shows up and kills two hired swordsmen. No one knows that Richard was hired by the Duchess of Tremontaine, who pretends to be only concerned with being the most dazzling hostess on the Hill. Really the Duchess is a master of political scheming, and she takes several men into her bed, and under her wing, teaching them how to win politically, and using them for her own goals. Currently, the Duchess is having an affair with Lord Ferris, the Dragon Chancellor of the High Council. The High Council is led by Lord Basil Halliday, the Crescent Chancellor, who worries that the nobles have too much power over the common people.

Lord Ferris seeks out Richard to try to commission him to kill Basil, so that Ferris can inherit Basil's position of Crescent Chancellor. When Richard is hesitant to accept the job, Ferris claims that the Duchess is his ally. Alec warns Richard to have nothing to do with the manipulations of one noble against another, and once again Richard wonders where Alec came from. He can tell that the young scholar comes from nobility, but Alec will say nothing. Instead, Alec picks fights wherever they go, so that Richard kills many men in Alec's defense.

The Duchess flirts with young Michael Godwin, who feels boyish and prissy compared to men like Basil. Michael secretly starts training with the sword, at the academy of Vincent Applethorpe, a retired swordsman with one arm. As Michael gains skill and discipline, he finds that he does not care about the decadent pastimes of young noblemen, and his character grows along with his skill. Lord Horn, one of the Council, tries to seduce Michael, who insults him in public. Goaded by Ferris, Lord Horn tries to hire Richard to kill Michael. Richard haughtily refuses, so Lord Horn has Alec kidnapped, promising to return him once Richard has challenged Michael. Richard finds Michael at his sword practice, but Applethorpe steps forward to take the challenge. They have a thrilling battle, but in the end, Richard kills Applethorpe.

Richard kills the kidnappers, then goes after Lord Horn. Alec disappears, and soon Richard is arrested for questioning about Lord Horn. At Richard's trial, Alec shows up in splendid clothing, and reveals that he is the lord of the House of Tremontaine, the Duchess's grandson. Lord Ferris, seeing that all is lost, claims to have paid Richard to kill Lord Horn, and is banished for lying about the Tremontaines. The Duchess tries to play Alec and Richard against one another, so that she can use them as tools, but they both leave her behind, and find one another again.