A young woman named Helen Stoner consults the detective Sherlock Holmes about the suspicious death of her sister, Julia. One night, after conversing with her twin sister about her upcoming wedding day, Julia screamed and came to the hallway where Helen came out to see her, in Julia's dying words she said "it was the band, the speckled band!" Julia had been engaged to be married and, had she lived, would have received an annual GBP250 annuity from her late mother's income. Now Helen's boyfriend has asked her to marry him. Helen tells that centuries ago the Stoner family was one of the largest landowners in England, but a series of wastrels in the bloodline have squandered both reputation and treasure. Holmes' investigation of the mother's estate reveals that its value has decreased significantly, and if both daughters had married, Dr. Roylott, Helen's ill-tempered and violent stepfather, would be left with very little, while the marriage of even one would be crippling. Therefore, the main suspicion falls on him.