一群生态学者，前往某沼泽地区采集水质样品化验以便作成环境评估报告。然而在这期间友人先后离奇失踪，终于得知是巨大鳄鱼所为，于是怀疑跟当地有人倾倒放射性废物有关。居住沼泽达三十年的乔闻后，而展开一场人鳄斗智斗力之争，鳄终于被消灭。

The famous writer Bernard travels to a small town nearby a lake to spend vacation out of season in the winter. He check in an old hotel owned by Enrico and his daughter Irma expecting to meet the maid Tilde, from whom he had a crush last time he visited the town. However, he discovers that Tilde has committed suicide and when he meets the local photographer, Bernard learns that she was pregnant. He becomes obsessed to find whether she really committed suicide and to guess what really happened. When Enrico's son Mario and his wife Adriana arrive at the hotel, Bernard has daydreams about the fate of Tilde.