On New Year's holidays, Andrei Lukin comes to the house of private detective Miroslava Volgina and demands to find... a ghost! In his distant youth, he spent the night with a girl, Zinaida, and only later learned that she died giving birth to his child. But now Andrei is sure that he saw Zina at a party the other day. He failed to get close to her - the girl ran away, losing her shoe. Miroslava does not take this strange story seriously. The New Year does not exist for such miracles! But soon Sister Lukina turns to the detective for help. Andrei is accused of murdering his fiancee! Now Volgina is really interested. Together with her irresistible friend, investigator Napoleonov, she will get to the bottom of the truth!