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.