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.

Javier Falcon, Chief of the Homicide Division in Sevilla, must solve two different cases in a short period of time. An old friend who has infiltrated an Islamic terrorist cell in Sevilla and whose son is now being aggressively recruited for their cause, seeks out Falcon's help. In the meantime, the Russian mafia that he's been investigating has kidnapped a child and the ransom they are demanding is far too high. As these cases intersect, Falcon must decide who he can trust and how he can protect those he loves most before time runs out.