There is a dark streak in the life of mathematics teacher Rita Roshchina - there is no personal life, she was fired from her job, there is no money... A chance meeting with a former classmate, it would seem, provides a chance to solve at least a financial issue: Boris invites Rita to be a little “private detective” and help him sort out his problems. Mathematics and private investigation, of course, are poorly compatible things, but nothing special was required from Rita - she was quite capable of portraying Boris’s girlfriend at the Catholic Christmas holiday, and she was quite capable of looking after her business partners. But no one imagined that the “New Russian” party in a snow-covered country house would turn into a bloody nightmare...