载人火星探险任务即将结束，探险队剩最后一天就要返回。但其中一人却心有不甘，决定留下来，寻找能证明火星生命存在的证物。重大发现出现在眼前，但悲剧也随之发生了，地表塌陷，他掉入了不明深渊。科学家们留下来，拯救他们的同事。然而，又有人消失了，难道他们发现的火星生命真的存在？On the last day of the first manned mission to Mars, a crew member of Tantalus Base believes he has made an astounding discovery - fossilized evidence of bacterial life. Unwilling to let the relief crew claims all the glory, he disobeys orders to pack up and goes out on an unauthorized expedition to collect further samples. But a routine excavation turns to disaster when the porous ground collapses and he falls into a deep crevice and near certain death. His devastated colleagues attempt to recover his body. However, when another vanishes, they start to suspect that the life-form they have discovered is not without danger.
