Kinsey reluctantly takes on the case of a missing doctor whose ex-wife is convinced that he ran off from his current wife--and while theories abound as Kinsey investigates, facts run slim.

When Lorna Kepler's badly decomposed body was found, the police couldn't discover cause of death. Only Lorna's mother kept the case alive because she thought it was murder.

Private investigator Kinsey Millhone puts herself in the gravest danger of her career when she is hired by the widow of Nota Lake detective Tom Newquist to discover what it was that had been bothering Tom in the last six weeks of his life before he died of a heart attack.

"Of #1 New York Times-bestselling author Sue Grafton, NPR's Maureen Corrigan said, "Makes me wish there were more than 26 letters." With only two letters left, Grafton's many devoted readers will share that sentiment. X: The number ten. An unknown quantity. A mistake. A cross. A kiss. X: The shortest entry in Webster's Unabridged. Derived from Greek and Latin and commonly found in science, medicine, and religion. The most graphically dramatic letter....

"Sue Grafton's X: Perhaps her darkest and most chilling novel, it features a remorseless serial killer who leaves no trace of his crimes. Once again breaking the rules and establishing new paths, Grafton wastes little time identifying this sociopath. The test is whether Kinsey can prove her case against him before she becomes his next victim"--