Fallen Legion, book four in the Timeless Series.

The full force of the Empyrean Guard leaves Gabriella trembling where she stands. Even with the Fallen at her back, she lacks the proper training and knowledge to win the inevitable Angelic War. In the Timeless Oblivion, Gabriella seeks the advice of the one person who’s never failed her. She comes back with more than she bargained for. Now Gabriella must do the unthinkable: break the most important law the Celestial Gods decreed thousands of years ago to protect the Angels. Now that she’s crossed the line, will she find a way to save the Angels? Or has she doomed them all?

Available in 2012.