一次大地震令洛杉矶地底深处的火山喷发，向着住宅区流去，维修地下管道的工人被烧死。地质学家艾美和朋友下去隧道勘测时亲身经历了朋友被岩浆喷发带走了生命。一时之间，城市一隅充满了地底爆发的岩浆。危机处理中心总指挥麦克（Tommy Lee Jones 饰）采取了艾美博士的建议开始疏散人群，他们先利用数百万吨空中降水来使来势汹汹的岩浆变成障碍物，阻挡了岩浆的流动。正当大家以为松一口气时，艾美博士认为岩浆...

Eight friends, all in stable relationships, venture into a game of sexual discovery by exchanging couples while trying to free themselves from their daily routines and add a spice to their love lives....