The Books of Cithara (Book 8, Progeny of Evolution)

Book Eight of the Progeny of Evolution series opens not at the beginning but near the end, the humble tale of vampire Cithara, oracle to renowned First Century Roman General and Emperor, Vespasian. Cithara, and her loyal mate, the wolfen Aliff, are an untraditional couple who hold the secret to procreation for their kind, known as The People. Together, they witness real and alternate historical events firsthand. 
 
While serving her master and dealing with the unique demands of family life for The People, Cithara meets a descendant from the twenty-second century, familiar to readers of other books in the series. The time traveler is sent back to correct a historical event that, if unchecked, leads to extinction-level nuclear war. Corrective attempts produce different future worlds, but result in the same sad end. Then, when all seems lost, Cithara receives inspiration from an unexpected source and makes a self-sacrificing decision.