The Turquoise Lament (Travis McGee)

Now that Linda "Pidge" Lewellen is grown up, she tells Travis McGee, once her girlhood idol, that either she's going crazy or Howie, her affable ex-jock of a husband, is trying to kill her. McGee checks things out, and gives Pidge the all clear. But when Pidge and Howie sail away to kiss and make up, McGee has second thoughts. If only he can get to Pidge before he has time for any more thinking.