In the forest wilderness, where predatory ursas rule, man is only prey.
The journalist Zhigulyov goes to the ominous reserve, where the Ursa bears rule monstrous creatures born of a mad experiment. Endowed with human intelligence, but devoid of morality, these mutant bears have become a nightmare for the locals.
Together with the hermit Krasnov, the only one who dares to oppose the Urs, Zhigulyov plunges into the abyss of horror and despair. But soon they fall into a trap, and Krasnov dies.
In his last hours, Zhigulyov is tormented by the question: what is man if he is capable of creating such evil?
«Ursa» is a chilling warning to scientists whose ambitions could lead to disaster.