Never kill anyone you know.

Never have a motive.

Never follow a discernible pattern.

Never carry a weapon after it has been used.

The first installment of Sandford's well-known crime series introduces detective Lucas Davenport, a man with a life ahead of him. On duty, he is a tough, ruthless Minnesota cop who abides by little or no nonsense from anybody. Behind the badge, nevertheless, is a successful entrepreneur who writes games for a living. And from a personal standpoint, not to mention, he is a raunchy, womanizing swinger who constantly jumps in love from one woman to another.

In the debut of this hit series by Sandford, Davenport is called in to investigate a series of murders committed by Louis "Maddogg" Vullion. To every body who closely knows Louis, he is a mediocre tax attorney struggling to make ends meet. But the other face of Louis is that of an obsessive madman who commits his killings by religiously following a meticulous set of rules. In attempt of serving as a challenge to Davenport, he leaves a note of one of his rules at each and every one of his crime scenes, such as the ones mentioned earlier. With one killing happening after another, the media and the Twin Cities are in a paranoid frenzy. Lucas, on the other end, decides to play by rules of his own...