This is one of those rare films that starts as a slog but grows progressively more engrossing as it develops. It finally delivers a wallop of a finale, a concluding 15 minutes crackling with suspense and left-field twists – but it’s really quite hard work at first, presenting a bewildering blizzard of dialogue that largely obscures what the hell is going on. It starts by introducing an enigmatic assemblage of shadowy politicians noshing and joshing together in a Spanish seaside restaurant. Gradually, party apparatchik Manuel (the intensely watchable Antonio de la Torre, whose middle-aged features are carved with dimples and oddly angled worry lines) emerges as the protagonist of an offbeat crime thriller seemingly set 10 or 15 years ago, when Blackberries were the upper-middle-class smartphone of choice and iPhones were just coming on to the market.

The technology is significant, coming into play as assorted means of surveillance are deployed by Manuel and his confederates to blackmail and betray each other. The contours of the corruption they have colluded in together become clearer as details leak out, although by the end some may still be wondering what exactly the bad things were that these guys did.

Ultimately it doesn’t really matter. The point is that although Manuel is just as greedy and venal as the others, he at least feels some redeeming familial loyalty to his wife (Mónica López) and teenage daughter (María de Nati) who are suddenly at risk of losing more than just their plush lifestyle. Director Rodrigo Sorogoyen, whose last feature May God Save Us earned positive reviews, finds a cinematic correlative to the growing sense of paranoia and panic in the jittering handheld camerawork and mosquito-like whine of the EDM soundtrack that grows incrementally more menacing.