It was a complete surprise for private detective Tatyana Ivanova when former classmate Irina Spitsyna called for help. For a whole month now, this young, harmless housewife has been terrorized by some telephone maniac, tirelessly repeating the same phrase: “You will soon die!” For the last time he names the exact date - her birthday. At the request of a friend, Tatyana comes to her party scheduled for that day. She can't wait to meet the narrow circle of guests...