The year is 2525, and the world has been turned upside-down. Monstrous airborne creatures known as the Baileys have driven the world's population underground, and taken over the Earth's surface.

Over centuries of Bailey domination, mankind's subterranean universe has grown into an immense labyrinth of shafts and corridors. The Earth's interior houses various levels comprised of different worlds, ranging from beautifully simulated surface environments to toxic waste dumps. The human populations inhabiting these domains have evolved independently over hundreds of years, giving rise to a vast array of diverse cultures. Bailey-engineered Betrayer robots, outwardly indistinguishable from humans, roam among the people, ready to warn their masters of any impending insurrection.

While most of humanity has abandoned hope of ever reclaiming the surface of the Earth, there are those who are still fiercely committed to that cause. Among these brave souls are the female warriors Hel and Sarge. They are joined by Cleopatra, who wakes up 500 years after being cryogenically frozen during breast implant surgery, and Mauser, the android that runs their lab. They are united in the most courageous of quests: to restore humanity to its rightful place on the planet.

But now the battle has shifted. After a major all out war between human kind and bailey kind, with neither side winning or losing, It's now Hel's enemy Creegan who governs the Bailey Race. His personal obsession with Hel is what this new season is mainly about. Creegan has the power to destroy it all in an instant and there's nothing the team can do about. What stops him from doing it?