本片取材于2004年印度洋海啸时发生的一桩真实事件。 玛莉雅(娜奥米·沃茨 Naomi Watts 饰)和亨利(伊万·麦克格雷格 Ewan McGregor 饰)带着三个儿子,一同前往泰国共渡圣诞佳节,不料就在圣诞节隔天,当这幸福的一家人在泳池旁享受着悠闲时光时,一股猛兽般的万呎滔天巨浪竟迎面袭来。被眼前景象震慑住的玛莉雅,一时反应不及,不幸惨遭巨浪袭卷;而尽管亨利及时抓住两个儿子准备逃亡, 一切仍旧太迟,凶猛的大水最后仍冲散了他们。一度被巨浪击昏的玛莉雅,醒来后发现自己正漂浮在海面,而原本围绕在身旁的所有景物,都已被淹没于水面下,她深信家人们皆已罹难的同时,竟发现自己的大儿子卢卡斯,竟然就漂浮在距离她仅有几公尺远的海面上。玛丽雅顿时犹如被打了一剂强心针,她决定想尽办法,要带着大儿子卢卡斯一起活着离开......A regular family - Maria (Naomi Watts), Henry (Ewan McGregor) and their three kids - travel to Thailand to spend Christmas. They get an upgrade to a villa on the coastline. After settling in and exchanging gifts, they go to the pool, like so many other tourists. A perfect paradise vacation until a distant noise becomes a roar. There is no time to escape from the tsunami; Maria and her eldest are swept one way, Henry and the youngest another. Who will survive, and what will become of them?