After introducing the egg-to-butterfly cycle of a Monarch butterfly, the author describes the work of Dr. Fred Urquhart and Norah Urquhart, scientists who have spent their lives researching the migratory behavior of these insects. When Ken and Cathy Burgger first located a central Mexican wintering site of the Monarch, the Urquharts and the author-photographer arrived soon after to study and document this long-awaited discovery. Full-page photographs aptly convey the overwhelming number of butterflies found at the mountain site. (Ages 9-12)