Can an adventure turn into the worst nightmare ever? Some university students let themselves be convinced by their teacher to live an adventure inside an anti-atomic bunker, in order to acquire useful information for their theses. The temperaments and diversities resulting from the girls' heterogeneous social backgrounds ensant an interesting, but, at the same time, complicated weekend. A sinister caretaker accompanies them to the heart of the bunker, considered one of the safest places in the world, from which they will not be able to get out for twenty-four hours. Amid amazement and restlessness, women camp in a fetid improvised dormitory. But during the night two of them disappear. Nora, the teacher, coordinates the research, which will soon suck the group into a deadly vortex concocted by the madness of a ferocious anthropophagus who, with unprecedented violence, disfigures them one by one and devours them.