 Unfortunately, the doctor's experiments have created mutant giant shrews that have escaped and are now reproducing in the wild, growing larger and more voracious by the day.The group must now barricade themselves inside their compound every evening before the sun sets, so that the shrews will kill each other once they have eaten every other living animal on the island.Thorne and Ann begin to be attracted to each other, causing Jerry to become jealous, despite ruining his relationship with Ann.