Tipping Point. A Folly Beach Mystery, #19

A peaceful kayak trip through the marsh suddenly turns terrifying for Chris Landrum and his friend, Charles Fowler, when a single-engine airplane plummets toward their watercraft. After coming inches from certain death, the kayakers' heroic efforts save two of the plane's occupants but failed to save the other two passengers. Learning the pilot had been poisoned and three of the plane's passengers live on Folly Beach, site of Chris and Charles's retirement homes, Charles, the self-proclaimed private detective, decides it's up to the two retirees to catch the killer.
While no simple task, it's made more difficult when they realize they don't know the identity of the intended victim or victims. Further complicating their undertaking, Chris is detracted when he learns another of his friends comes face-to-face with a life-altering secret going back a half-century. Once again, Chris and his cast of quirky characters are challenged to solve a crime the police are unable to unravel before lives are lost, possibly their own.