Private detective Tatyana Ivanova is stumped. A married couple places two identical orders: in the first case—discover who the wife is cheating with; in the second—who the husband is cheating with. Hardly had Tatyana managed to solve that “two unknowns” problem, when suddenly a new twist of events occurs. Vladimir Tselikov, one of the clients, is murdered in the courtyard of the house of his lover. Who is the killer? And what is the purpose of the killing? The investigation leads Tatyana to conclude: there is a bloody fight over Tselikov’s inheritance—his priceless collection of antiques. And now a point has been put in this difficult case. But at the very end of this story, Tatyana is in for one more surprise…