本片根据一桩真实事件改编。在1975年11月5日晚上，在亚利桑那州的荒野山林中，五位伐木工人宣称亲眼目睹他们的同伴崔维斯（DB史威尼饰）被天外幽浮给绑架了。镇上居民认为他们头脑有问题，当地警长（詹姆斯嘉纳饰）则认为他们是在掩饰一桩命案，这种说法是要妨碍警方调查。然而，事情的真相自然唯有当事...
生活在芬谷林的精灵们的世界一度很大，但因为人类的破坏，大自然失去了平衡，森林几乎被毁灭。很多年后，随着时间的慢慢推移，森林逐渐恢复生机，作恶多端的恶魔奥克斯也被囚禁于大树之下。也是从那以后，芬古林再也没有出现过人类，精灵们也过着悠闲的生活。仙女克瑞斯在一个偶然的机会下，飞出密林，见识到了她从未看见过的世界。并把黑烟囱的事情告诉了芬谷林的先知瑞切。
芬谷林的上方笼罩着不祥的烟雾，瑞切知道人类的破坏和污染又开始了。一只头脑不清醒、语无伦次的蝙蝠无意中闯入了芬谷林，带来了人类破坏自然的坏消息。克瑞斯抑制不住好奇心，决定飞去看个究竟。克瑞斯从来没有见过人类，当她看到了人类——年轻的伐木工扎克时，却阴差阳错把他变成了和自己一样大小。但是芬谷林有了麻烦，扎克所在的伐木队要对这个森林进行砍伐。
更糟糕的是，无意中伐木队解放了被囚禁在树木中恶魔奥克斯。危险一天天逼近，但生活在芬谷林的精灵们对此却毫无察觉。被带到芬谷林的人类扎克逐渐适应了变小的自己，与克瑞斯等人也成为了好朋友。原本对树木不爱惜的他在克瑞斯实际行动的感召下，慢慢具有了爱护树木的意识。同时，他也认识到自己所在的伐木队正在做一件多么错误的事情。
伐木队被恶魔奥克斯所控制，意图毁掉芬谷林。许多树木遭到了人为的破坏，扎克十分难过，决定尽力组织这一切。先知瑞切为了挽救树林，情愿牺牲自己，把生长的力量分给了其他精灵。面对强大的奥克斯的侵犯，扎克和全部精灵齐心合力，终于保卫住了森林。而扎克最终也变回了正常大小，但从此以后他作为人类的一员，将为保护森林而做出终身的奋斗。
Hank Stamper and his father, Henry, own and operate the family business by cutting and shipping logs in Oregon. The town is furious when they continue working despite the town going broke and the other loggers go on strike ordering the Stampers to stop, however Hank continues to push his family on cutting more trees. Hank's wife wishes he would stop and hopes that they can spend more time together. When Hank's half brother Leland comes to work for them, more trouble starts.
Tornionjokilaakso at the end of the 19th century, Paloniemi's landlord Heikki tries to get out of his financial difficulties with the help of his son Juhan and Nuottaniemi's only daughter Hanna. The happiness of Hanna, who has fallen in love with Antti of Rehti Koskenalusta, is threatened by the evil and dangerous Korpikoski.
Jim Sherwood , toughest logging boss in the timber country, takes on his toughest assignment when he agrees to cut an enormous volume of timber for Andrew MacKinley, who has to deliver the timber within sixty days.
Eetu, a wealthy homeowner, attempts to seduce Leena Kosken. But when austere log boy Erkki meets her at midsummer dances, Leena falls in love with him instead. Jealous, Eetu turns the men of the village against Erkki and the Tukki people.
A group of scouts stumble onto a cache of stolen weapons hidden in a forest. They meet up with a girl and get involved with the men who originally stole the weapons. The men try to shoot the scouts every time - but are thwarted at the end.
California logger Bill Cardigan must save his stand of redwoods from being bought by unscrupulous Dan Fallon, a logging company owner from Michigan.