The company of cheerful, noisy youth decides to spend the coming weekend in nature, choosing for recreation a reserved, secluded place, far from the city and other places inhabited by people, to stay away from the city noise and extraneous interference. The guys are students of a medical college and want to relax on the warm day in the fresh air, restore strength after difficult exams and a difficult school year. There comes a long-awaited day and buddies leave far away from the gassed city streets and bored, strict teachers to enjoy a relaxed, friendly fellowship, to feel the absolute freedom from daily duties relating to learning. Travelers are conveniently located in a chosen place, breaking a tourist camp, where they plan to spend an unforgettable pastime. Six light-hearted tourists did not expect that the planned event would soon become a horrible nightmare. Unexpectedly, on the carefree, relaxed tourists, an unknown wild animal attacks, which inflicts terrible bites on all present. Through the wounds inflicted by the teeth, an unusual beast infects its victims. Infected blood begins to circulate through the veins, producing a monstrous effect on the human body. Struck by a strange virus, students are transformed into bloodthirsty cannibals, trying to feed themselves on the flesh of anyone who finds himself in the way of a person. A friendly picnic begins to resemble a bloody carnage in which former friends are allowed to hunt one another in order to satisfy a sudden, insatiable hunger. Beastly, wild instincts completely absorb the brutal monsters.