An elite security team assigned the task of protecting the last known woman who can become pregnant, find themselves caught in an endless claustrophobic underground tunnel system. The team soon learns - the real horror is not the unstoppable force chasing them, but the ever growing smaller tunnel itself. 一组精英团队在执行一次任务中,被困在了一个封闭的管道中,通过他们的机智和勇敢最终取得胜利...