"Your husband is sleeping with your student" - Olga finds this note in one of the bouquets she received to celebrate her triumphant performance at a scientific forum. Olga is a mathematician. She easily calculates who sent this anonymous message. The only problem is that they find this person dead. Thus begins a dangerous game, where each move is connected to one of the numbers in the Fibonacci sequence. What do they signify and how are they connected to Olga's life? The answer lies far in the past. Every mistake will cost someone close to the heroine their life.