When political intrigue drove Louis Morgon from a successful career at the State Department, he moved to a cottage in France, far from Washington and what he called "the sordid world." He took up painting. He grew vegetables and flowers. He ate long, lovely meals on the terrace overlooking fields of sunflowers. He thought that he had found happiness. Then one day Louis's past lands squarely on his doorstep. It does so in the shape of a dead man. His...