Trapped in a confined space, Mason and his team face a relentless mutant brown rat that is trying to force them out by ramming their hiding spot. As the rat corners them, Mason identifies its weakness in the abdomen, confirming it’s no ordinary pest. Meanwhile, Gary spots Evelyn, a popular campus girl, with a mysterious man nearby. Despite pleas to help her, Gary insists on focusing on the dangerous rat, which has killed several allies. The team decides to let others tire the rat before making their final strike, leaving their fate uncertain as the mutant rat closes in.