The novel, one in a series of novels by Bernard Cornwell, chronicles the trials and tribulations of Rifleman Major Richard Sharpe of the British army. Torn with guilt after the death of his wife, whom he did not truly love, Sharpe accepts the challenge of a duel from El Marques—-the husband of Helene Leroux, a woman with whom he is obsessed. Sharpe would have won the duel but is prevented from killing El Marques by Lieutenant Leroy, his commanding officer, who arrives just in time. Sharpe claims the duel was a matter of honor, but even Patrick Harper, his closest friend, cannot understand why Sharpe would jeopardize his career and well-being for something so ill-advised. The evening after the duel el Marques is murdered, and Sharpe is convicted of the crime though he is innocent. General Wellington of the British forces arranges for a switch, so another man dies in Sharpe's stead, and he is sent to discover why he has been framed for the Marques's death. Helene Leroux, or La Marquesa, had written a letter via the instruction of Pierre Ducos claiming Sharpe threatened her, and this letter is used as major evidence against him. He and a Spanish boy named Angel set out to find her and learn the truth. She has been kidnapped by Ducos, Father Hacha the Inquisitor, and his brother El Matarife, and taken to a convent. Since she is a widow, if she becomes a nun, all her great fortune goes into the church. Sharpe rescues her from the convent but oversleeps in a small town and is captured the next day. Just before El Matarife can fight him, the French army invades the town, including La Marquesa's lover, General Verigny. She lies about Sharpe's identity to keep him safe because he absolutely cannot be caught as Richard Sharpe, since that man is supposed to be dead. General Verigny wants Sharpe to sign a parole promising he won't try to escape, but Sharpe does not, so he is kept in a disgusting prison cell for safekeeping when they arrive at Burgos. Sharpe is then brutally interviewed by Ducos, who admits that he set Sharpe up to be blamed for the murder, as payback for a time before when Sharpe broke his eyeglasses. He, in turn, breaks Sharpe's beloved spyglass given to him for saving Wellington's life, but Sharpe uses one of the brass pieces to overcome his enemy and Ducos flees. Sharpe encounters Verigny again who is appalled at Ducos's treatment of the prisoner and quickly provides him with food, water, a doctor, and a change of clothes. That evening, La Marquesa, Verigny, and Major Montbrun try to convince Sharpe to sign the parole so he can be treated in a way befitting his status as a man. La Marquesa later returns alone, informs Sharpe about Ducos's treaty, and tries to convince him to sign the parole and escape to warn Wellington. She only wants to regain her wealth, which is held by the army. Sharpe is extremely conflicted, but the next morning decides he cannot in good conscience sign his parole. There is a terrific explosion and he is able to escape but is hurt and cared for by a nearby Spanish family. Meanwhile, the French are retreating to Vitoria, and the British army is in hot pursuit. Though still injured, Sharpe sets off the next morning to rejoin the army and almost runs into El Matarife and his men. Luckily he is reunited with Angel, and the two set off to warn Wellington of the treaty. The British are camped just outside Vitoria, and each side gears up for battle. The British emerge victorious; the French flee, and Sharpe must rescue La Marquesa once again from El Matarife, who admits that he killed the Marques.