Former district attorney Patsy Rand collapses and dies at a mystery book club meeting. Before dying she utters the word "yellow." From that small clue the mystery grows. The police ask former private investigator Milo Rathkey to consult on the case. The victim wrote a book years ago accusing a software guru of murder. The books are disappearing. Milo wonders if the book collector and the murderer are one and the same.