The interplanetary gates have existed between the five planets and the Netherworld for as long as living memory. Dr. Elisabeth Avery is a woman caught between two worlds. Little does she know that others like her, other half-breeds, are being hunted. When a creature drags a princess into the Netherworld, Elisabeth is determined to save her by any means necessary. Meanwhile, on the planet of Hystera, a Keeper and his assistant investigate a grisly string of suicides and are in need of someone with Elisabeth's skills. The Gate Guardians and Elisabeth are aware that something is coming and know that it has something to do with the Netherworld bleeding through to the planets, but not why. Will Elisabeth be able to come to terms with who she is in time to face the coming threat?