This time she's headed to Mexico to observe Diana Vega-a former museum curator who now leads tours through the spectacular Monarch butterfly sanctuaries. Diana's past work with a particular museum collection, combined with some recent unexplained activities, has quietly caught the CIA's attention.
Posing as just another retiree eager to witness one of nature's most breathtaking migrations, Evelyn joins Diana's tour group in the mountain forests outside Mexico City. But as orange and black wings dance around her, Evelyn must determine if there's more to Diana's career change than a simple love of butterflies. In her latest assignment, Evelyn discovers that even the most innocent-seeming activities can mask deeper mysteries. And in these peaceful sanctuaries, someone may be using nature's beauty as the perfect cover for something far more complex.