The following version of the book was used to create this study guide: Bayard, Louis. The Pale Blue Eye. HarperCollins Publishers, New York, NY, 2006. Kindle AZW file.

Gus Landor is a retired police detective who moved to the New York countryside for his health. One day, Landor is summoned to the nearby West Point campus because one of the cadets apparently committed suicide by hanging himself. The mystery military officials want Landor to solve is who cut Cadet Leroy Fry's heart out a few hours after his death. Landor agrees to take on the investigation, but asks that a young cadet named Edgar Allan Poe be assigned to help gather information. Military officials are not convinced Poe is a good fit, but give in to Landor's request. Poe agrees to help despite the fact that he will not be paid, must work in secret, and has to keep up his normal duties and studies.

Landor becomes skeptical of some of Poe's stories, as the military officials have been all along. Poe claims that his parents were famous actors who died in a theater fire. Landor had actually seen Poe's mother on stage once, and Poe is anxious to hear every detail Landor can recall. Landor sends a request for a friend to gather information about Poe. Later, Landor learns that many of Poe's stories are lies.

Despite those personal lies, Poe and Landor have already worked together to find significant pieces of information. They become convinced that Artemus Marquis is involved. He is the son of the base physician, Dr. Daniel Marquis. Poe attends dinner at the Marquis home and falls in love with Artemus's sister Lea. Poe and Landor come to realize that Lea suffers from an illness that results in seizures. As they continue their research, a second cadet is found murdered. Randall Ballinger's heart and testicles are cut away, making Landor comment that this murder must have been highly personal. A few days later, a cadet named Julius Stoddard disappears. Everyone assumes his body will soon be found, but a fisherman reveals that Stoddard actually left the campus and caught a steamer out of the area. The mystery seems to be resolved when Artemus and Lea kidnap Poe and take some of his blood – the blood of a virgin – for a ritual. Lea has been communing with a dead ancestor who is telling her that Fry's heart and a virgin's blood will bring an end to her seizures. Landor sets out to rescue Poe. Lea chokes while trying to swallow the heart. The underground room catches on fire, and both Lea and Artemus die there.

The mystery is resolved to the satisfaction of the military officials, but Poe arrives at Landor's house with the news that he has put together an entirely different set of clues. One of these is a poem dictated to Poe by Landor's deceased daughter Mattie. What Landor has not revealed is that Fry, Ballinger, and Stoddard attacked and raped Landor's daughter Mattie. Though her physical wounds healed, Mattie committed suicide. Landor discovered Fry's identity and killed him on the West Point campus. Artemus and Lea merely took advantage of the presence of a dead body to get a heart for their ritual. Landor then accepted the role of investigator, knowing this would give him the opportunity to find the names of the other two assailants. He discovered this through Fry's diary, but Stoddard realized the danger and fled before Landor could kill him. Landor spends the next few months writing down the details of these events. He leaves them with the knowledge that someone will eventually find this, and he falls to his death in the same place that Mattie fell.