Beneath Cairo lies a city that has never appeared on any map. Layla Ashraf has spent a year underground, bonded to a dragon carrying five hundred years of hidden history, standing between two worlds that were never meant to meet.Now the fire she carries has a name, a purpose, and an enemy that has been waiting centuries to claim what it knows.The organization wants the memory. The splinter wants the power. The Hollow Ones want something no one expected. And the boundary between the hidden city and the surface world - the boundary Layla has been protecting, studying, and slowly dissolving - is about to break open entirely.She has the bond. She has the archive. She has a Commander who stopped managing his expressions four months ago and hasn't looked back.Some bonds cannot be broken. Some fires cannot be buried. Some things, once found, cannot be unfound.The Hidden Flame: Eternal Flame is the breathtaking conclusion to the Hidden Flame series - epic fantasy set in the hidden heart of Cairo, where ancient magic meets modern scholarship, and the oldest fires are the ones that last forever.