When a squirrel named Mina finds a mysterious green ball with a hairy little creature inside that calls her mamá, she decides to take it in for the night and try to find its mother the next day, but the search turns out to be more complicated than expected.

Invites readers to follow along as Mr. Postmouse delivers letters and packages to all the animals on his route.

"Mail Mouse goes on vacation with his family, but he never stops delivering packages and letters. Whether he journeys to the jungle, the North Pole, the beach or the desert, he spreads joy wherever he goes and introduces readers to different habitats with each leg of the trip" -- Amazon.com.