Book: The Taken King.
“You know, I give her a lot of guff. But there aren't five Warlocks in the Tower that coulda done what Eris did today, getting the Guardian out like that. Damn good work, and now they're all ready to take on the King. Just remember, Eris' creepy and condescending manner makes her all kinds of unpleasant to deal with. I don't want to make this collaboration thing a habit.” - Cayde-6