The Shadowed Oracle by R.B. Sturn

This is no Prophecy.
It is only Survival.

When twenty-seven-year-old Ingrid Lourdes receives a series of ominous messages, the mysteries of her past quickly unravel, and the nightmares she suffered from all her life are made flesh. She is catapulted into a new world full of immortals, wraiths, cursed monsters, a raging religious war, and a secret society of beings just like her called world-walkers – living on Earth, but driven from their home world of Ealis.

With the help of Dean Crassus, one of the leaders of this secret army of world-walkers, she is forced into a Homeric series of misadventures. Fighting a scourge and the creatures it brought with it. Seeking allies in storied kingdoms. Infiltrating a magic-wielding usurper’s court. And all the while, running from a ruthless Prince, and the even crueler High King he serves, to save not only herself and this new world, but the humans she left behind on Earth.