Eternals Book 1: Lucy's Nightmare - The Eternals, #1

The first book in the Eternals series. The Eternals are a superior race of supernatural beings who have roamed the earth for thousands of years in search of a place where they could find peace. These vampire like creature don't need human blood to exist. Instead, they absorb the life force from their victims in order to remain young and powerful. After settling into a new home, Paris (once a scientist and explorer from Ancient Greece), Paulo (once a soldier to Nero in the Roman Empire) and Selene (once a handmaiden to Cleopatra in Ancient Egypt) discover Lucy Johnson, a battered young wife surviving in the mountains in post Civil War northern Georgia.
The Eternals find it imperative to help Lucy out of her critical situation before it's too late.