A man in bandages, endowed with incredible strength, kills a local professor of biology. The girl, claiming that she is the daughter of a professor, imposes her help on the operatives, but she is only interested in the yellow bag, which was with Herman. At the crime scene, the Dog finds a thermos with an unknown liquid. Having sipped it, Gnezdilov gains super-endurance. Who or what is hiding under the bandages and why are scientists dying?