Investigating a distant planet, a group of interstellar explorers stumbles across a bizarre alien with breeding on its mind. To that end, it assaults team member Sandy (Judy Geeson), leaving her pregnant. Now, driven by the voracious needs of her unborn "child," Sandy develops an insatiable craving for her colleagues' flesh. With a ferocity only a mother protecting her young could muster, Sandy cannibalizes her crew with bloody abandon.