June, 1981, Galveston Harbor. Historian Urban McLean, newly retired from the American Embassy in Bogotá, takes his yacht Aluna on a speaking tour of the Gulf Coast from Texas to Florida. He’s reenacting characters and incidents of an ill-fated Spanish expedition here in 1528, led by the mercurial Pánfilo de Narváez, a flawed character McLean portrays all too easily. Joining the tour: McLean's half-Colombian daughter on college vacation; an exiled Bolivian family friend; a young Floridian fisherman; two FBI agents under cover.  All come to the tour with different agendas, but other events—near and far—entangle them, with deadly consequences. Along this historic coast, the seamarks of the lost Narváez expedition are haunting reminders that disaster can stalk even the best-laid plans.