Thunderbolt, the son of Perun, wanders through the earthly and Eternal worlds in search of the stolen spring. With her loss, the annual cycle is broken, and endless winter threatens the death of all humanity. Meanwhile, somewhere far away, a new, unknown spring is already sleeping, but it can awaken only after the battle of the sons of Perun and Veles. And they have been looking for each other for a long time, approaching the crossroads of winter and summer in different ways. It is there that the battle must take place, which will finally restore the destroyed world order.