The girls Asya and Matilda have long been friends with the wonderful guys Kostya and Mitya. Their party was different from others - because it was called, no more and no less, "Detective Bureau "Quartet". They had time for everything - jokes, kisses, noisy parties. And, of course, for investigating crimes. Real ones. Like, for example , a mysterious story with a car explosion, the kidnapping of its owner and... strange brown ampoules with some kind of miracle drug...