Shipwreck survivors are found on Beiru Island (Infanto tô), which was previously used for atomic tests. The interior is amazingly free of radiation effects, and they believe that they were protected by a special juice that was given to them by the island's residents. A joint expedition of Rolisican and Japanese scientists explores Beiru and discovers many curious things, including two women only one foot (30 centimeters) high. Unscrupulous expedition leader Clark Nelson abducts the women and puts them in a vaudeville show. But their sweet singing contains a telepathic cry for help to Mothra, a gigantic moth that is worshiped as a deity by the island people. The giant monster heeds the call of the women and heads to Tokyo, wreaking destruction in its path.

这部灾难影片背景以现代日本为中心，主要描写东京突然被一股莫名的浓雾所笼罩，整个都会好像一下子消失了似的，各地政府及科研人员因此极为震惊，急忙组织起来研究对策。但是人们却无法穿越浓雾进入东京首都圈。这场浓雾形成了一个无法穿越的电磁屏障。而圈外的科学家们则在受损严重的军用侦察机上得到灵感，利用即将到来的台风和雷暴雨，加上人工大功率电磁干扰机，终于化解了这场戏剧般的非自然危机。 这原本该是一个不错的富裕,富足,殷实,丰裕戏剧张力的构思，但拍出来的片子却教人不敢叫好，剧中女记者的角色刻划不具感染力，而她和男记者之间时好时坏的关系描写也让人感觉莫名其妙，确是让观众感觉象一场雾。