As a study in motiveless malevolence Jaume Balagueró's domestic chiller is as toxic as they come. Luis Tosar plays a lonely concierge in an upscale Barcelona apartment building. Incapable of happiness himself, he dedicates his time to destroying that of his unsuspecting residents via a subtle program of sabotage.
Poisoning pets and framing colleagues are all in a day's work, but it's a cheery young woman named Clara (Marta Etura) he's really got it in for, sneaking into her apartment at night and creating all kinds of malignant mischief, simply because he wants to "wipe the smile off her face".
Balagueró stretches suspense as taut as piano wire, tightening it by degrees, and adds a gratuitous twist of horror in the concierge's account of these barbarities to his voiceless, hospital-bound mother. The old dictum "Misery loves company" has seldom been given a more unsavoury or gripping illustration.