从恢复起来的记忆里,陈源如愿以偿地得知苏云是喜欢他的,他们青梅竹马,看到她笑,他会知道是因为什么;看到她微微蹙眉,他也会马上知道她担心的是什么;他也知道她爱吃什么,喜欢什么颜色,爱听什么样的歌。A young newlywed couple find themselves trapped in a network of underground caves. With her husband injured, the new bride is forced to find her way back to the surface in order to save his life. In the process, they discover a terrifying truth about the "underneath", they are not alone. Something evil is hunting them.