U is for Undertow. A Kinsey Millhone Novel

Sue Grafton takes the mystery genre to new heights with this twisting, complex #1 New York Times bestseller that draws private investigator Kinsey Millhone into a case shrouded in the sins of the past. Looking solemn, Michael Sutton arrives in Kinsey Millhone's office with a story to tell. When he was six, he says, he wandered into the woods and saw two men digging a hole. They claimed they were pirates, looking for buried treasure.
Now, all these years later, the long-forgotten events have come back to him-and he has pieced them together with news reports from the time, becoming convinced that he witnesses the burial of a kidnapped child. Kinsey has nearly nothing to go on. Sutton doesn't even know where he was that day-and, she soon discovers, he has a history of what might generously be called an active imagination. Despite her doubts, Kinsey sets out to track down the so-called burial site.
And what's found there pulls her into a hidden current of deceit stretching back more than twenty years...