It all begins when fellow P.I. John Henning is found dead, an ostensible suicide. In his will, Henning leaves half of his earthly possessions to Polo (the other half to the Catholic Church and Alcoholics Anonymous), and names Polo his executor. A Key leads Polo to a local bank and Henning's safety-deposit box, where he discovers a cache of "drops of oil," priceless Colombian emeralds. But where would Henning, a lone-wolf P.I., have gotten the money to buy such exotic jewels? And why would a recovering alcoholic choose to end his own life when it seemed to be on the upswing? With the assistance of local reporter Jane Tobin, his on-again, off-again lady friend, Polo begins a search for the answers that will explain Henning's death, a search that takes him to the home of a woman whom Polo suspects may have been one of Henning's last clients. There's only one problem, the woman is dead. That's one death too many for Polo, who is determined to catch the killer in a case sparked with Kennealy's special humor and intrigue, undoubtedly inspired by the author's own firsthand knowledge of the true professional investigator's trade.