克拉拉（麦肯芝·弗依 Mackenzie Foy 饰）的母亲在她很小的时候就离开了她，留给女儿的唯一一样东西是装有无价之宝的盒子。德罗赛尔梅耶（摩根·弗里曼 Morgan Freeman 饰）是克拉拉的教父，在他举办的一场聚会上，一根神秘的金线指引着克拉拉找到了可以打开盒子的钥匙，然而，克拉拉却因此而被传送到了一个神秘的平行世界之中。 　　这是一个克拉拉的母亲一手打造的魔法世界，四位国王分别掌管着他们的国度，而克拉拉梦寐以求的钥匙，就掌握在其中最邪恶的一位——姜母女王（海伦·米伦 Helen Mirren 饰）的手上，她的存在让这个本来和平繁盛的世界逐渐走向分崩离析。克拉拉必须和她在这里结识的善良朋友们合作，夺回钥匙，粉碎姜母女王的统治和野心。All Clara wants is a key - a one-of-a-kind key that will unlock a box that holds a priceless gift from her late mother. A golden thread, presented to her at godfather Drosselmeyer's annual holiday party, leads her to the coveted key-which promptly disappears into a strange and mysterious parallel world. It's there that Clara encounters a soldier named Phillip, a gang of mice and the regents who preside over three Realms: Land of Snowflakes, Land of Flowers, and Land of Sweets. Clara and Phillip must brave the ominous Fourth Realm, home to the tyrant Mother Ginger, to retrieve Clara's key and hopefully return harmony to the unstable world.