: A colonel is being killed in a military town. Sherlock Holmes discovers that the killer is a man whom the colonel betrayed in order to destroy and marry his bride.

In the small town of Oldershot, where a military unit is stationed, they kill Colonel James Barclay, a valiant veteran who began serving as an ordinary soldier and was promoted to officer for bravery. In his youth, Barclay married the daughter of a sergeant in his regiment, Nancy. Having lived thirty years, the couple were considered an exemplary couple. The colonel was madly in love with his wife, she treated him more evenly, they had no children. Mrs. Barclay used the location of the regimental ladies, and her husband - colleagues.

The Barclay family, with several servants, occupies a villa in which guests are infrequent. A few days ago, Mrs. Barclay, in a good mood, left with her friend Miss Morrison at a meeting of the charity society in which she was. When she returned home in a bad mood, she locked herself with her husband in the living room, and the servants heard her calling him a coward and uttered the name “David” several times. Suddenly, a terrible cry was heard, the roar and cry of the mistress. As the inner door was locked, the servants rushed to the glass door overlooking the garden, which, fortunately, was open.In the room on the sofa, the hostess was lying unconscious, her husband was dead, his head was broken with some kind of blunt weapon. An unusual hardwood baton, which did not belong to the colonel, lay nearby. Police found that the murder was committed by her. The door key also disappeared. The interrogation of Miss Morrison, with which Mrs. Barclay had been with all this time, gave nothing. The girl did not know what could cause a quarrel between the spouses.

Having studied all the details of the case, the police are at an impasse. Sherlock Holmes arrives at the scene of the crime, who is interested in this case. He draws attention to the fact that the face of the deceased is distorted by fear. Neither the colonel nor his wife had the key, therefore, there was someone else in the room, and he took the key. A stranger could only enter a room through a glass door. On the lawn there were footprints of shoes, and on the curtains there were footprints of a small animal that was with an unfamiliar visitor. Seeing a cage with a canary at the top, the animal climbed up the curtain.

After weighing the facts, Sherlock Holmes draws conclusions. Standing on the road, a man sees how the Barclay spouses quarrel in a lighted room with raised curtains. Having run across the lawn, the stranger enters the room with the animal and hits the colonel, or the colonel, frightened, falls himself and hits the back of the head against the fireplace. The stranger leaves and carries the key.

Given that Mrs. Barclay left home in a good mood and returned upset, Sherlock Holmes suggests that Miss Morrison is hiding the truth. Frightened that Mrs. Barclay could be charged with murder, Mrs. Morrison says that on the way home they met a stray humpback cripple who turned out to be Mrs. Barclay's old acquaintance.The woman asked Miss Morrison to leave them alone. Catching up with a friend, Mrs. Barclay said that this man was very unlucky in life, and asked her not to tell anyone.

Finding a hunchback in a small military town where there are few civilians is not difficult. It turns out to be a wandering magician, a cripple named Henry Wood. He once served in India in the same regiment with James Barclay and was considered the first handsome regiment. Both were in love with Nancy, and she loved Henry. Young people wanted to get married, but then a riot began in the country, and the regiment was under siege. Henry volunteered to make his way to his own, and James Barclay, who knew the area well, advised him on the best way. Making his way, Henry was ambushed. From the conversation of the rebels, he learned that Barclay had betrayed him. Retreating, the rioters took Henry with them. After torture, he became crippled. While wandering, Wood learned magic tricks and thereby earned his living. In old age, Henry was drawn to his homeland.

Having met Nancy, who considered him dead, he followed after her and from the street saw her quarrel with her husband, throwing accusations of betrayal in his face. Henry could not stand it and rushed into the house. Seeing him, Colonel Barclay fell and hit the fireplace, and Nancy lost consciousness. Taking the key from her hands, Henry wanted to call for help, but realized that he could be accused of murder. He hastily put the key in his pocket and wanted to leave, but his mongoose, the beast with which he shows tricks, climbed up the curtain. Trying to catch him, Henry forgot his stick.

The case is closed - according to the examination, death came from an apoplexy blow. Dr. Watson, however, does not understand why Mrs. Barclay uttered the name "David" if the deceased was named James and the hunchback was Henry.To which the great detective replies that if he were the very ideal logician that Watson describes him, he would immediately have guessed what the matter was: the name was thrown into rebuke, by analogy with the biblical king David.