2013. A mysterious epidemic spreads across the planet; humanity develops an irrational fear of open spaces which causes death within seconds. Soon, the entire global populace is trapped inside buildings. As Barcelona descends into chaos, Marc sets off on a quest to find Julia, his missing girlfriend - without ever venturing outside.

Apartment concierge Cesar (Luis Tosar) is a miserable person who believes he was born without the ability to be happy. As a result, he decides his mission is to make life hell for everyone around him. A majority of the tenants are easy to agitate, but Clara (Marta Etura) proves to be harder than the most. So Cesar goes to creepy extremes to make this young woman mentally break down. Things get even more complicated in this twisted relationship when her boyfriend, Marcos (Alberto San Juan), shows up.

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?