Private detective Tatyana Ivanova is puzzled. Two similar orders come from a married couple: with whom they cheat, in the first case - the wife, in the second - the husband. Tatiana barely had time to solve this problem with “two unknowns” when suddenly there was a new turn of events. One of the customers, doctor Vladimir Tselikov, was killed in the courtyard of his mistress’s house. Who's the killer? And what is the purpose of the massacre? The investigation leads Tatiana to the conclusion: there is a bloody battle for Tselikov’s inheritance - a rich collection of antiques. And now the end has been put in this difficult matter. But at the very end of this story, another surprise awaits Tatyana...