A murder mystery set in a retirement community in Chapel Hill, NC. During a bridge game at the club, one of the members, a Nobel-laureate in Economics, keels over and dies after receiving a perfect hand of 13 diamonds. An old mathematician, Lillian, who is present at the table, suspects this was a well-planned murder and starts unraveling the mystery (which turns out to be related to embezzzled funds and death bequests). Along the way, she explains a bit of combinatorics, a game of strategy involving toothpicks and binary arithmetic, a ball-weighing problem, a substitution code and remarkably, the Konisberg Bridge problem which is part of the solution to identify the murderer (spelled out using City of Bridgeton).