The Bill is Coming Due... ... on Project Hyperion. Ariane Austin discovers she and her friends Marc, Simon, and Wu Kung are crippled after their battles in Challenges of the Deeps, unable to use their Arena-born powers. The newly-embodied Hyperion AI, Dr. Alexander Fairchild, is working with a Molothos officer to undermine the Faction of Humanity... while he also pulls deadly strings back home in the Solar System. The insane Hyperion Maria-Susanna is active at last, and someone has murdered one of the Champions of the Arena even as he was coming to meet with Marc DuQuesne. All of these events are related, and the collision of such forces will shake the entirety of the Arena, and beyond, as they find that everything, everything, is affected by the long, dark shadows of Hyperion.