Stel Caine faces the greatest challenge to her hope yet. Meanwhile, Tajo returns to her family home on Salus, only to find a city on the brink of devastation. There is no food, no air, no hope for mankind's last great dome city. Now, Tajo must band together with Io, a man carrying a secret millennia old, and Mertali, a brave mermaid from the gladiator pits of Poluma, to fight for a better future for everyone. It all ends here in this second oversized hardcover, featuring a ton of designs, layouts, scripts, and other never-before-seen treasures, as writer RICK REMENDER (BLACK SCIENCE, DEADLY CLASS, SEVEN TO ETERNITY) and artist GREG TOCCHINI (Uncanny X-Force) conclude their tale of mankind's final hour in the cold, deathly dark of the sea! Collects LOW #16-26.