Plot
In January 1903, at Baker Street, James M. Dodd comes to Holmes with a strange story regarding his friend, Godfrey Emsworth. Dodd and Emsworth served in the Imperial Yeomanry in South Africa during the Second Boer War. Emsworth was sent home after being treated for a bullet wound; hearing nothing from his friend for quite some time afterwards, Dodd began to suspect something was amiss.
Dodd wrote to Colonel Emsworth, Godfrey's father, and was told Godfrey had gone on a voyage round the world for his health. Dodd found it odd that Godfrey himself had not written to him about this matter, and managed to convince Godfrey's mother to invite him to the Emsworth family home, Tuxbury Old Park, near Bedford. There were four people there—the Colonel and his wife, and an old butler and his wife. The irritable Colonel repeated the story about his son's world voyage, implied Dodd was lying about knowing Godfrey, and abruptly refused Dodd's request for Godfrey's contact information.
That evening, in the ground-floor bedroom, Dodd talked to the butler, Ralph. After Ralph mentioned Godfrey in the past tense, Dodd asked if Godfrey was dead, to which the butler replied "I wish to God he was, Sir!" After Ralph had left, Dodd was considering what the phrase might mean, when he suddenly saw Godfrey's face looking in on him through the window. Godfrey's skin was blotched white in places, and when he realized he had been spotted, he fled into the night. Dodd pursued him, but stopped after hearing a door slam in the distance.
Determined to solve the mystery, Dodd contrived to stay one more night in Tuxbury Old Park. While exploring the estate, he met a small, well-dressed man coming out of one of the outbuildings. The man also indicated Godfrey had gone away, but Dodd later noticed the man watching him suspiciously. Fearing that Godfrey was being held against his will in the outbuilding, Dodd secretly returned to the building at night and looked through the window. He spotted the well-dressed man reading a paper in one chair, and Godfrey sitting in another chair, his back to the window. At this point, Colonel Emsworth discovered what Dodd was up to, berated him for violating the family privacy, and ordered him off the premises.
After hearing Dodd's story, Holmes asks two questions; one, to clarify Godfrey's strange blanched appearance, and two, what sort of paper the well-dressed man was reading, though Dodd is uncertain of the answer to the second question. The two agree to return to Tuxbury Old Park in a week's time.
Upon his arrival at Tuxbury Old Park, Holmes observes Ralph removing a pair of tarry-smelling leather gloves, indicating the presence of disinfectants. The Colonel threatens to summon the police if Dodd and Holmes do not leave, but Holmes points out that this would make the family secret public. He writes the word "leprosy" on a piece of paper and shows it to the Colonel; realising that Holmes knows all, the Colonel agrees to grant Holmes and Dodd an interview with Godfrey.
The young soldier orders them to keep their distance while he tells his story. When he was wounded in South Africa, he had dragged himself to a nearby building and slept in a bed there; in the morning, a doctor on the premises found him, and informed him that the building was a leper hospital and that Godfrey was in danger of catching the disease. Godfrey was sent to a regular hospital, and later back home to England; however, some weeks later, white blotches began to appear on his skin. Fearing he had caught leprosy, and knowing that he would be forced into segregation in a leper colony if the British authorities found out, Godfrey and his parents decided that he should hide. The well-dressed man staying with Godfrey is Dr. Kent, a sympathetic local general practitioner who agreed to keep the Emsworth's secret.
The story ends happily. With Dr. Kent's permission, Holmes brings Sir James Saunders, a famous dermatologist from London, to see to Godfrey. Sir James determines that Godfrey is not a leper, but is suffering from ichthyosis, an unsightly but non-contagious treatable disease.
