Every year, over 100 million North American monarch butterflies embark on an epic 2000-mile flight to Mexico, where they will spend the winter. This fascinating "Nova" program chronicles their amazing two-month journey, from the birth of the monarchs to their celebrated arrival. Stunning, detailed images of their travels reveal how these delicate creatures survive the treacherous trip. 56 min. Widescreen (Enhanced); Soundtrack: English Dolby Digital stereo.