Unraveling the knots of woven intrigues and solving riddles is her job. The main thing is that the riddles are ancient and the knots are sophisticated. Yielding to the pressure of an energetic customer, she takes on a job unusual for her - to prove that the lady’s husband, a deputy, is of noble origin. But her search for the politician’s famous ancestors leads her to the trail of a crime committed during the years of the revolution. And an attempt to restore the truth, albeit a hundred years late, unexpectedly turns into new tragedies...