Mathematics textbook for the 5th grade. According to the conditions of the problem, every day a Pedestrian goes from point "A" to point "B", on the way he meets a Cyclist. Then he returns home, where his faithful wife is waiting for him. The next day everything repeats. But one day the Investigator stops the Pedestrian and reports that the Cyclist has disappeared. The Investigator asks the Pedestrian to go with him to point "B" in order to interrogate witnesses and figure out this complicated story together.

In late 18th-century Russia, village life is shaped by a fusion of rural superstitions, pagan beliefs and traces of Orthodox Christianity. Twin girls are violently separated when one is believed to be possessed, accused of draining the vitality of her sister. Meanwhile, a young man, branded a freak and outcast, obsessively constructs mechanical wings in a desperate attempt to fly like Icarus. Overseeing this turbulent world are Europeanised feudal lords who maintain brutal, cynical control over the peasants, exacerbating class tensions.