故事從一位年輕的小偷開始，當她注視著包包裡滿滿的種子，她才明白自己許下的，是什麼樣的承諾。她決定踏上旅程：一段改變自己和其他人世代以來生活的旅程。
相信人與大自然的關係對每個人都是很重要的，現今的世代，我們比起過去更加需要延續這樣的和諧關係。這是一個神奇的、關於「發現」的故事，它會觸動每一位讀者的內心和想像，無論是年輕人，或是老年人。
作者利用美麗、簡潔卻又充滿力量，並且真誠、抒情的文字，喚醒了世界與人之間，自然和諧共處的願景；並且藉由繪者的細膩圖像，帶領讀者一同經歷這位年輕女孩的旅程，從一座苛刻、現實的城市開始，感受那股改變世界的美麗力量以及旺盛活力。
A picture book of great beauty and hope about the power we have to transform our world. On a mean street in a mean city, a thief tries to snatch an old woman's bag. But she finds she can't have it without promising something in return - to "plant them all". When it turns out the bag is full of acorns, the young thief embarks on a journey that changes her own life and the lives of others for generations to come. Inspired by the belief that a relationship with nature is essential to every human being, and that now, more than ever, we need to renew that relationship, The Promise is the story of a magical discovery that will touch the heart and imagination of every reader, young and old. With poignant simplicity, honesty and lyricism, Nicola Davies evokes a powerful vision of a world where people and nature live in harmony. And Laura Carlin's delicate illustrations capture a young girl's journey from a harsh, urban reality to the beauty and vitality of a changed world.
文字作者妮可拉戴維斯本業是動物學家，從小對動物有著莫大的熱誠，這份熱誠一直延續到成年，她目前較為人所知的身份是童書作者，但其實她在三十九歲才出了第一本童書，至今有三十餘本著作。大部份的作品和動物脫離不了關係，這本《承諾》乍看之下和動物無關，但其實是和大自然有密切連結的故事。
2014英語協會圖畫書獎（Engish Association Picture Book award）
2015美國綠地球圖書獎（The Green Earth Book Award）
2015英國凱特格林威獎選書（The CILIP Kate Greenaway Medal Shortlist）
