The story is based on an Indian urban legend that tells of a Muslim who was forced to have his arm amputated after an accident, and died a few months later, but after death became a ghost and began wandering about in search of his limb.
The central character of the story is a doctor, Sir Dominic Holden, who has had a long spell of service in British India first as a military doctor and then as a private surgeon in Bombay. Once when he was posted at Peshawar, then a main city of undivided Punjab (hence a part of India), he had to attend a poor Afghan whose one hand was in such a bad state due to the growth of a gangrene, that the only way to save his life was to amputate it. The operation was performed and Dr. Holden asked for the amputated hand as his fees. Dr. Holden had a hobby of collecting discarded limbs, organs, cysts from living and dead humans and thus wanted to add the "brown hand" to his collection. The Afghan being Islamic, refused to part with his amputated hand, as it breached the rule of his religion which stated amputated body parts to be kept with the owner himself. But Dr. Holden promised to return the Afghan his hand before his death and took the hand with him to his house in Bombay. Dr. Holden retired soon after and settled in Wiltshire. Then one night he was awakened by someone pulling his clothes - the ghost of his old Afghan patient. Dr. Holden understood that the Afghan had died and his ghost wanted back the amputated hand. From then onwards, the ghost haunted the doctor's lab every night for four years looking for his hand. But the ghost failed to find the hand since it had been damaged in a fire that broke out at the doctor's house in Bombay. The recurring visit of the ghost, however, had made the life of Dr. Holden and his wife, Lady Holden, miserable and the effect on their health was prominent. A doctor known for his steel nerves had now become a scared individual.
The protagonist of the story, Dr. Holden's nephew, Hardecar decided to solve this problem. He spent his first night in the lab and saw the Afghan searching his hand. The next day, Dr. Holden explained him everything in details and Hardecar left for London. Hardecar, a doctor himself, went through a book on spirits and found that certain spirits could not leave the living world because of them being strongly attached to something or someone existing in this world. Hardecar decided to try his luck and left for Chadwell where a friend of his was the home surgeon at a hospital for sailors. The home surgeon provided Hardecar with an amputated hand of an Indian sailor as the requirement was a "brown hand".
Hardecar returned to Wiltshire and placed the hand in a jar and placed it in his uncle's lab. Hardecar stayed awake as the Afghan ghost came visiting as usual. But Hardecar's experiment failed as the Afghan on seeing the hand, wailed in agony and smashed the jar on the floor before disappearing. Next morning, Hardecar realised his mistake as he had brought the left hand of the sailor while the Afghan had had his right hand separated. Hardecar rushed back to Chadwell and luckily got the right hand of the sailor. He returned and placed the hand in a jar in the lab just like the previous day. Dr. Holden forbade Hardecar from sleeping in the lab as he feared risking his nephew's life.
That night, Hardecar again saw somebody approaching him while he tried to sleep. But it wasn't any ghost but his uncle who seemed overwhelmed with joy and had suddenly regained some of the energy he possessed earlier. Dr. Holden stated that the ghost had finally found his amputated hand and before leaving, he had bowed thrice in front of him, in a way similar to how Afghan's pay respect. The Holdens lived on peacefully and consulted Hardecar for every major decisions they took thereafter. Before he passed away, Dr. Holden named Hardecar as the heir to his property.