Mai wants to free the sparrows caged outside the temple gates, but she can’t afford to pay for their freedom. Instead, she gives a gift to the girl Thu, chanting, “Fly free, fly free, in the sky so blue. When you do a good deed, it will come back to you.” Thu goes on to do a good deed for another, and a cycle of good deeds carries readers through the book, beyond Mai’s village and back again. The book is set in Vietnam and draws on the Buddhist tradition of freeing creatures for good karma. Thong has done her research, but the book is an effortless read, and the illustrations are disarmingly simple, foregrounding the heart of the story.