Dan Reilly, a farmer working in rural Ireland, is propositioned by a local bio-genetics firm to assist in some experiments to make faster growing cattle. The experiments go awry and one of Dan's cows births a calf that is already pregnant with six malformed feti with fangs and exoskeletons. Orla, a local veterinarian, kills the calf and unwittingly allows one of the still living feti to escape during a necropsy. John, the scientist conducting the experiment, discovers that the cells of the feti are replicating far too quickly and that the missing fetal creature has the potential to infect cows as well as humans globally, causing a massive infestation of the bloodthirsty creatures. They are now on a mission to kill the creature before it escapes from the farm.