Cases of infected animals appear near one of villages in Sumava region. Virologist Pavel Rogl, that is in his thirties, has task to inspect the situation, supervise the vaccination and find the source of infection. He is also charged to elaborate an expertise for team of police detectives, who are investigating mysterious double homicide, that happened in nearby forests. It is possible, that murders are connected to infection. Young scientists get in touch with his former classmate Gabriela and her sister Tana. As their father is suspected from commitment of brutal murders, they start their own investigation. The more they discover, the more they attract attention of murderer, that neither wants to be revealed, nor arrested. Body count grows and burdensome secret from post war history of village is being slowly revealed.

Bucina village in Sumava region is paralyzed by appearance of rabbies. After virologist Pavel Rogl publishes shocking news, that bear could be responsible for double homicide by cabin in the forest, everybody takes him as a fool, until it it proven, that he was right. Where from did the dangerous beast escape? And who is pulling the strings in background?

Searching for perpetrator of murders puts other disturbing facts in the way. Old Pudil is killed by his own dogs infected with rabbies. Why does the perpetrator leave symbols on his victims? Who lured Gabina's sister to cabin in the night out? Will Pavel make it up with Gabina?

Body of Honys has finally been discovered, even with another corpse, that is way older. Clue leads to history of perished village. Pavel Rogl gets in life threatening danger, he is saved by unexpected arriver. Will police finally arrest escaping murderer? Or will his body count grow up?

A loop around Machar is finally closed. History provides its testimony and reveals horrifying reality. Pavel Rogel gets in deadly danger..