A gloomy sky with hanging clouds of a strange color, puddles of green suspicious-smelling liquid everywhere, dilapidated buildings and broken cars - this is all that remains of the once actively working base in Toxic Arena: Biological Threat. It turns out that secret experiments on human mutation were conducted on its territory. When the explosion occurred, the area became contaminated, and mutants burst to the surface. To localize the threat and prevent the monsters from spreading throughout the area, the hero was sent to eliminate them in Toxic Arena: Biological Threat.
