Sanctuary - Guardians of the Time Stream, #2

Ess Fremont and the Blue Lotus Society know the Originators have been infiltrated by Revisionists, their ancestral enemies in the quest to rewrite or protect history. The treachery has reached even to their headquarters, Sanctuary, an underground complex near San Francisco. Problem: The Society can't contact Sanctuary, or risk putting power into the enemy's hands. Yet Ess must go there to claim her heritage and learn how and why her grandparents vanished seven years ago.
All her answers, and a vital weapon in the battle against the Revisionists could lie in her grandparents' vault -- and Ess herself is the key to open it. Solution: Ask her family lawyers to "turn her in, " and on the train ride cross-country, begin her education. The journey launches revelations that threaten everything Ess knows as truth. As she uncovers schemes within lies within treachery, the fulfillment of her family's destiny rests heavy on her shoulders. Who can she trust when her own grandparents blocked her memories, and the means to save or destroy them all are hidden in the vaults of her mind? GUARDIANS OF THE TIME STREAM: set during the reconstruction of the United States in the decades following the Civil War. Technology is on the rise, with locomotives and steam-powered industry, airships and other experiments in slightly anachronistic technology.
A fascination with travel around the world and the exploration of other cultures, especially ancient cultures, is on the rise. The Guardians, who call themselves the Originators, are descendants of travelers from our far distant future, who traveled into the distant past to prevent another group of time travelers from altering the world to suit their vision. And as Ess Fremont grows up and learns her heritage, her family's history and their secrets, she takes her place in the battle to protect the world.