The boisterous, arrogant professor Challenger, a reputed biologist and anthropologist, dares the London Zoological Society to mount an expedition to verify his spectacular claim, without physical proof, that his previous expedition to the Amazonian basin found live dinosaurs. Apart from him and his 'socialite' counterpart, professor Summerlee, it consists of experienced discoverer Lord Roxbury, the young reporter Ed Malone -who got publicly struck down with Challenger's umbrella at his arrival- and Jennifer Holmes, Malone's news agency's boss's daughter, essentially as conditions for putting up the money. In Brazil they are joined by Jennifer's brother David and local 'guide' Manuel Gomez. They soon discover the dinosaurs are real and dangerous, like giant spiders, but loose their helicopter and thus are desperate for a way down from the isolated plateau. They learn Roxbury knew about the fate of Burton White, an explorer whose diary they find, thus presume to be dead, in search of diamonds, and confirmation of the local tribe being the lethal guardians of the plateau's secrets, but also get surprising help...

音乐教师Christine Radcliffe原以为 Karel Novak 在战争中被杀害，她是如此的爱他，一直坚持与他携手共老。可是当Karel 再次出现的时候，等来的却是来自他爱人的一颗子弹..

帕里斯（罗伯特·卡明斯 Robert Cummings 饰）和德雷克（罗纳德·里根 Ronald Reagan 饰）是青梅竹马的玩伴，虽然他们的性格大相径庭，但两人之间的感情却非常的要好。帕里斯爱上了医生亚历山大（克劳德·雷恩斯 Claude Rains 饰）的女儿卡桑德拉（贝蒂·菲尔德 Betty Field 饰），然而，卡桑德拉却被严厉的父亲软禁在家中，十分的痛苦。　　那边厢，个性轻浮的德雷克邂逅了名为路易斯（南茜·科曼 Nancy Coleman 饰）的女子，当德雷克前往路易斯家提亲时，他因为自己的风流韵事而遭到了路易斯家人们的拒绝。之后，德雷克又遇见了兰迪（安·谢里登 Ann Sheridan 饰），虽然兰迪出身于一个非常贫穷的家庭之中，但是两人还是很快就坠入了情网。

二战刚刚结束，莉亚（英格丽·褒曼 Ingrid Bergman饰）作为战犯的女儿被美国联邦调查局相中，利用她对父亲罪恶的负疚和其父在纳粹阵营内的关系网络，深入调查纳粹首脑契巴斯（克劳德·雷恩斯Cl