Unlocked at level 10, like the guy above me said. Angela, Sally, and Enok will then have quests you can start that give you a tome in your consumables. Just be super careful about what tome you pick, as unfortunately you won't be able to walk it back without deleting the character and starting over from level 1. There really should be a class re-spec, I ended up getting screwed over by my dyslexia and had to start over.