Sunset Towers is a new apartment building on Lake Michigan, north of Milwaukee and just down the shore from the mansion owned by reclusive self-made millionaire Samuel W. Westing. (Despite its name, Sunset Towers faces east – into the sunrise.) Sam Westing was a wealthy businessman who made his fortune in paper products. He was very patriotic and never smoked, drank, or gambled.

As the story opens, Barney Northrup is selling apartments to a carefully selected group of tenants. He claims that chess is not allowed in the building. (This is a big clue, as Sam Westing loved chess.) After Sam Westing dies, at the beginning of the book, it emerges that most of the tenants are named as heirs in Westing's will. The will is structured as a puzzle, with the 16 heirs challenged to find the solution. Each of the eight pairs, assigned seemingly at random, is given $10,000 cash and a different set of baffling clues. The pair that solves the mystery will inherit Westing's entire $200 million fortune and control of his company. It is discovered that Berthe Erica Crow is the answer but not the murderer. In the end, unknown to the other players, Turtle Wexler wins the game and inherits Sam Westing's company.