What does Fitz feel he is half of and how is Burrich dealing with Fitz's feelings?

Fitz is still part wolf in his mind, and he is living at the home of Heart of the Pack, Burrich. Nighteyes, the wolf who has bonded with Fitz, is nearby, and wants Fitz to come hunt with him. Burrich does not allow Fitz to behave like a wolf, and is working hard to make Fitz remember that he is not Changer the Wolf, but Fitz, a man, who died and has come back.