Robert and Sharon are retired teachers who make a yearly pilgrimage to the idyllic Mexican town of San Miguel de Allende. They are committed to their annual trip, almost as much as they are committed to each other. Their journey to San Miguel often corresponds with the migration of the monarch butterflies to the Michoacán state. But this year is different. Robert has been diagnosed with prostate cancer, and the couple must now question their continued travels, as well as their remaining time together. Cancer can be a quick killer, and no one can guarantee Robert's health or how much time he has left. Even so, the magic of Mexico calls, and the couple finds it difficult to resist, despite Robert's declining strength. Mexico provides a temporary remedy for their bitterness and anger aimed at the unpredictability of life-a bitterness that must pass in order for their love to endure. Just like the monarchs, they too must migrate, sooner or later.