Omega City / Peterfreund, Diana

Seeking to prove her father is not a mad conspiracy theorist, Gillian Seagret, her brother Eric, best friend Savannah, and NASA-obsessed schoolmate Howard uncover the secret doomsday bunker of Dr. Alysius Underberg, a Cold War-era rocket scientist. Exploring the bunker, which is called Omega City, the four friends learn they are not alone, and before they know it they are in a race to find the answers to Dr. Underberg's questions, before Gillian's father's enemies get a hold of them first.

Gillian Seagret and her friends, while speaking at Guideant Technology after their adventure in finding Omega City, uncover evidence that the Shepherds, a mysterious orgainization that will stop at nothing to keep Dr. Underberg, and Omega City, a secret, have a secret base and it is up to Gillian to expose them before it is too late.

To save her father's reputation, Gillian Seagret must explore Omega City, a vast doomsday bunker deep inside the Earth.