Fine-arts dealer Edmund Carstairs is being harassed by a queer man in a flat cap, his home has been robbed, his family threatened, and murders uncovered. The only men who can help him are Sherlock Holmes and Dr. John Watson. The two investigators are drawn into an international scandal ranging from the criminal leagues of Boston to the foggy streets of London, all tied together by the mysterious phrase "the Silk House," a scandal threatening the very makeup of society.