四只翅膀和一个祈祷者

In eastern Canada, a Monarch butterfly emerges from its cocoon and spreads its wings. Soon, it will undertake a breathtaking 2,000-mile migration across North America, to a sanctuary nestled in the volcanic mountains of Mexico.
　　It is a journey filled with peril - but one that the Monarch executes flawlessly. Incredibly, the butterflies that make this greatest of all migrations will only travel this route once.