I'm gonna make you wish that you’d stayed gone

Mercury had witnessed packs fall before. Both the pack of his birth, and the first one he had joined after their death. The Hallows was a strong pack, but underneath Mercury's exterior, he could not deny that coiled fear. He did not want the Hallows to fall. He would do anything he had to to keep that from happening. So he well understood Art’s feelings, as they faced what was left of the pack known as Norad. He had not known its wolves, but he mourned this loss all the same.

At Art’s quiet words, he nodded briskly. “Understood” he told his lord, taking his place at Art’s side. He would defend the pack that had become his ally, and he would fight alongside Artorias in any battle the man wished. When Art raised his voice in a summoning howl, Mercury joined his voice to the call.

"Speech"