The Zero Secret. The Zero Enigma, #10

A thousand years ago, an empire died.  No one knew why.  Not until now. Seven years ago, Caitlyn "Cat" Aguirre - the first of the magicless Zeros - was kidnapped and taken to the ruins of the Eternal City.  There, she discovered the dread secret behind the collapse of the Thousand-Year Empire, a secret she knew she didn't dare share with the world.  But now, with strange sightings and energies emitting from the ruined city - and a darkening political situation back home - Cat has no choice, but to return to the dead city.  And what she finds there will change everything ...