The story
Exiled for the blood in her children's veins.
Annie is human, and loving Fenrir the wolf king and bearing his twin half blood daughters gets all of them driven out, on prejudice and on Mara's scheming. Five years later the twins' werewolf blood wakes up without warning and drags the whole family back into power struggles and hunts. Following it back, Fenrir finds out what really happened, and while he keeps his wife and daughters standing he goes after the one who arranged all of it.