Murro Vogt has stayed on Terra Firma, gathering some familiar faces during this time; as he acts as a remaining herald to the returning gate-keepers, Sandra, David and of course, Cassie. No sooner are they back and rejoined by Charlie and Sylvia, do they find themselves embroiled in defense against growing packs of the demon-possessed; transformed humans taken over by receiving the mark of the Beast rivaling any Zombie Apocalypse!
The mark is not all that's received, as Cassie and Sandra get more visions; this time to one of the century's military marvels; the Russian Ekranoplan, whose home just happens to be the Caspian Sea. One sunken, others mothballed on the Caspian Naval Base, it becomes their mission to procure and operate these leviathans as arks in the harvesting of Earth's last remnant of humanity.
Just as before the Earth-Gate, opposition builds against the Cross-Over, by the dark forces of the Beast and his conspirators; this time sinking to tactics such as a 'dream-napping' of Sandra, holding Cassie as hostage even demanding Shepherd to submit himself and destroy the arks.
A startling revelation as to the true origin of the Cross-gate is revealed, not to mention the advent of another pivotal dual-personhood, not unlike Cassandra herself; the one called Evada, who comes to play their unique role in the monumental event that is the Cross-Over.