Appraiser Rachel (Lindsey Shaw) receives the news that her top-notched client wants to buyout a small town's beloved library to build a resort and spa on the land. Rachel is completely against the idea of leaving NYC but loses the argument to her boss. So Rachel packs her bags and flies out to California. During her first visit to the library she runs into writer, Jake (Derek Theler), who is researching the tale of Captain Black Bart's hidden treasures for his next novel. With hopes of saving the library, Mrs. Archer (Rachel Ticotin), the librarian, pushes Jake to show Rachel what the library means to the town. Jake's already got a lot on his plate with his research and taking care of his niece, Hailey (Chiara Aurelia), and nephew, Noah (Max Page), for the summer but he agrees to help out. As Rachel learns what the library means to the community she must find away to save it before it's too late.

　　故事的背景是公元前二百万年，恐龙的石器时代，某个小镇住着一群石器时代的原始人，但他们的意识却非常现代。聪明的弗雷德用石头、动物骨骼和毛皮制作出电话机、照像机甚至影印机。家庭厨房设备还有以猪提供动力的环保型垃圾处理装置。

　　经过了两年的共同生活，如今斯图亚特和乔治一家过得融洽和睦，斯图亚特还是一如既往的聪明精灵，然而内心却为了一件事有点不安——乔治母亲添了小女儿，他们对这个千金宠爱有加，几乎花掉全部时间精力。而乔治功课也日渐繁忙，陪伴斯图亚特的时间也少了。斯图亚特有点落寞，直到它遇上了鸽子玛格罗。
　　斯图亚特上演了一幕英雄救美，把玛格罗从危难中解救出来，并带她回家疗伤，心里对她暗暗倾慕。然而斯图亚特的恋爱并不是特别顺利，他不知道玛格罗有着不为人知的秘密，这只机智勇敢的小白鼠面临着又一次充满挑战的冒险。

　　作家巴里（约翰尼·德普 Johnny Depp饰）正处于灵感枯竭期。他每天经过公园的时候，都会看见里面有一帮小孩在嬉戏。他停下脚步来观察，原来孩子在玩海盗游戏，孩子们还热情邀请他加入海盗队伍。巴里成了一个大孩子，在队伍中虽然高出一个头，却玩得不亦乐乎——道具、角色、各色 情节、公园变成一个快乐的幻想世界。这段经历，成了巴里创作《小飞侠》的灵感源泉。
　　孩子的母亲（凯特·温丝莱特 Kate Winslet 饰）是一个寡妇，她也受到了这里快乐的气氛感染。巴里和他们相处就像一家人一样，享受着单纯的快乐，然而也难免招人闲话。而巴里的妻子，也终究只属于现实世界，走不进巴里的内心。
　　《小飞侠》的完稿上演，遭到了众人的质疑。然而演出后当地的反响，证明了巴里的坚持是正确的。但这时，巴里和孩子们正面临着一场来自现实世界的巨大打击，他们善良的母亲，正在离他们远去……