「這本書超級神祕，連書名都不能告訴你。不但書名是祕密，連故事內容也是個祕密。很抱歉，我連故事發生在哪個國家都不能說。至於主角名字…那就用假名吧！」
　　神秘兮兮的旁白賣了許多關子，才開始介紹主角：凱絲是一個聰明又機警的女孩，她的背包裡天天都放著手電筒、指南針、乾糧、地圖等配備，有人會說凱絲是杞人憂天，不過她知道這些東西總有一天會派上用場。麥斯是個邏輯思考很清楚的男生，他非常愛說話，更喜歡講笑話─雖然都不好笑。某天，凱絲發現了一個上面寫著「嗅覺交響樂」的神祕木箱，裡頭裝滿許多小玻璃瓶，打開瓶蓋一聞，有薄荷、青草，甚至有臭雞蛋的味道！這個神祕箱子，原來跟一個魔術師有關…而且，還為凱絲和麥斯引來奇怪的敵人！(文／史黛拉)
　　What’s that smell? It smells a little like, hmm, a book you should definitely read! Why? Because this is a story about a secret, but it also contains a secret story.
　　When adventurous detectives, Cass, an ever-vigilant survivalist, and Max-Ernest, a boy driven by logic, discover the Symphony of Smells, a box filled with smelly vials of colorful ingredients, they accidentally stumble upon a mystery surrounding a dead magician's diary and the hunt for immortality.
　　Filled with word games, anagrams, and featuring a mysterious narrator, this is a book that won't stay secret for long.