Milky Way, thirteenth millennium of the stellar age.
Human beings have long since left the surface of the Mother Planet, Earth, and so much time has passed they barely remember it.
They have established themselves as the predominant form of life among the stars and all the while they expand, colonize and multiply undisturbed. At times they are at peace, other times they quarrel with one another in an endless strife of meaningless skirmishes.
But one day the balance is broken. A terrible alien race, relentless and apparently unstoppable, now threatens to upset this delicate order and wash away over twelve millennia of progress and expansion.
People in the Milky Way call them Herem, the Anathem…

BOOK TWO: THEM AND US

Araia Research Starbase, Orion Nebula. Emra is a brilliant scholar, a man who traveled the galaxy far and wide and lived on dozens of worlds. He is solitary and extremely jealous of his work, especially now that he's working for the army, trying to pry the secrets behind the Herem's very existence and feeling close to a sensational discovery. But now, a group of young PhD candidates from the Otamendi Academy has reached Araia, looking to upgrade their resumes. They are determined and willing go well out of their way to surpass their companions, and some of them have taken an interest in Emra’s study of “cerebros”: a colorful name for the mysterious Alien organisms which seem to be responsible for the Herems’ thought processes.
Meanwhile, the shadow of a terrible epidemic looms over Araia and its population. Just when he feels he's getting close to a breakthrough… Emra could very well be out of time.