柯恩被美国徵召到远洋海岛进行一个扫雷行动，出到岛上，柯恩立刻察觉事有蹊跷。柯恩的手下在扫雷时意外炸破一栋建筑物，外星人向他们攻击，众人逃出，在洞外又发现一个老人，老人率众人到他居住的洞穴。在洞内，柯恩得知在1995年时，飞碟坠毁，美军派员到岛上进行研究，外星人反击，研究组全死于非命，仅留下老人，柯恩设计将外星人陷住，并安排逃离岛外的木筏…

　　Scientists at a secret underground complex have found a way to travel to another dimension. Three dimension-travellers are the first to go through the gate - but are soon attacked by something that interrupts the communication with Earth. This horrible something uses the gate to travel back to the underground complex. Most of the staff are evacuated, except four heavily-armed militaries and Dr. Casserly and Dr. Summerfield who just can't stand each other...

　　Scientists at a secret underground complex have found a way to travel to another dimension. Three dimension-travellers are the first to go through the gate - but are soon attacked by something that interrupts the communication with Earth. This horrible something uses the gate to travel back to the underground complex. Most of the staff are evacuated, except four heavily-armed militaries and Dr. Casserly and Dr. Summerfield who just can't stand each other...