Robert Adrian is back with Countdown Citadel, the latest installment in the Sam Austin Chronicles. Citadel, a nation on a distant world founded by immortal former Apollo astronaut Sam Austin, is thriving now that disgraced former US President Courtney Harrington and her followers are dead. Harrington's threat that a hostile race of aliens would invade Citadel is no more, allowing the nation to be settled and settlements to become permanent. Citadel is also preparing to branch out to the nearby planet Shiloh. But before they can, a new group of people calling itself Phoenix joins the race to colonize the planet. Phoenix claims to have the same technology as Citadel-despite the latter's extreme technological secrecy. Citadel ambassador J. W. Preacher tries to warn Austin about the approaching dangers, but is too late. Meanwhile, other nations refuse to become involved in a dispute between Phoenix and Citadel. Will the growing conflict consume Austin and his comrades before they truly learn just how dangerous Phoenix is?