Torment (Fallen #2) by Lauren Kate

LOVE NEVER DIES . . .

It took Lucinda an eternity to find her beloved angel, Daniel. 
But he waited for her. Now they are forced apart again, to protect Luce from the Outcasts - immortals who want her dead. During their separation, Luce learns about her mysterious past lives. But the more she discovers, the more she suspects that Daniel is hiding something.

What if Daniel's version of the past isn't true?
Is it really their destiny to be together?
Or is Luce actually meant to be with someone else?

The thrilling sequel to the international bestseller, FALLEN