After a vague catastrophe called the Collapse decimates the United States, the survivors take refuge in seven city-states across the country and establish a totalitarian new regime. Citizens are grouped according to their “lifephase,” all conversations are recorded and stored in “the Vault,” and the country is run by a bloodline of seven senators. When one such senator dies, he bequeaths a sealed letter to his grandson, Zeke Thomas, which could cast doubt on the family’s lineage and prevent him from eventually assuming power. The narrative alternates between Zeke’s story, set in 2143 in a dystopian Texas teeming with political schemers and revolutionaries, and that of his ancestor, Zadock Thomas, set in 1840s Texas.