Aderan was supposed to be in the Celestial Moon pack, because he would be the messenger between the two packs and also 'Cane's eyes' there. He couldn't return to the pack without further instructions from the Alpha.
Therefore, for him to come here, there must be something going wrong.
"What are you doing here?" Ethan was very surprised to see Aderan here, as he raised his voice which made the latter frown.
"I didn't know that you dislike me so much," Aderan said sullenly.
Ethan rolled his eyes, but it was Jace, who stirred the conversation back to the main problem. "You shouldn't have returned without any instructions from the Alpha."