: Parents hide a young man who fought in Africa, and do not allow him to communicate with people. Sherlock Holmes discovers that the young man is mistakenly considered a leper, and brings a doctor to him who is taken to cure him.

Retired military officer Mr. James Dodd is turning to Sherlock Holmes. While serving in the army, he became friends with Godfrey Emsworth, the only son in the family. In one of the battles, Godfrey was wounded and sent to a hospital. First, friends corresponded, but then correspondence broke off. Mr. Dodd turned to Godfrey's parents. His father, Colonel Emsworth, wrote a rude reply in which he informed that Godfrey had gone on a world trip and would return no sooner than in a year. Mr. Dodd did not satisfy this answer; he wrote to Godfrey's mother, and she invited him to visit them. Arriving, Mr. Dodd continued to question, but received no reply.

In the evening, a butler came into his room, who began to question how Godfrey fought. He and his wife raised a young man and treated him like a son. In the conversation, the butler spoke of his young master as a dead man and hinted that it would be better if he died. Suddenly, Mr. Dodd saw Godfrey with a dead white face.

Mr. Dodd decided to examine the estate.In one of the many buildings, he met a bearded man who, learning that Mr. Dodd was a friend of Godfrey, felt that Godfrey had left. Here in the building window, Mr. Dodd saw Godfrey. Appearing Colonel Emsworth clearly hinted that the nearest train to London was leaving soon. Having quarreled with him, Mr. Dodd left and now asks the great detective for help.

A few days later, Sherlock Holmes with Mr. Dodd and his acquaintance set off for the Emsworth estate. Arriving opens a butler. Holmes immediately notes that in his hands are leather gloves with a characteristic tar smell.

When the colonel finds out about the visitors, he wants to call the police and drive out uninvited guests, but the great detective shows him a piece of paper on which something is written, and Mr. Emsworth leads the guests to Godfrey.

The face of the young man is disfigured by white spots, and the bearded man who is near Godfrey forbids approaching him. Being wounded in Africa, Godfrey was hospitalized for lepers and was infected there. Now he lives at home under the supervision of a doctor in complete isolation.

The great detective immediately realized that Godfrey was ill with something and therefore they were hiding him, and when he heard about his white complexion, he realized that it was leprosy, which he wrote on a piece of paper. He brought with him a specialist dermatologist who wants to examine the patient.

Inspection shows that the young man has no leprosy, but another skin disease that is not contagious and can be cured, albeit with difficulty.