The answers would be forever lost after the Duke's death, but Damian was still curious about the mysteries surrounding Glen's son, the one who got lost in the dungeon.
So, he wanted to find other ways to get the answers, and perhaps helping Glen find his son would become a way better decision after knowing that
"Does his family know about something, or are they also lost?" Damian thought.
Damian still did not know if these secrets Glen's son had were true, or if his family knew something about it, either. Maybe the Duke was just spitting bullshit before dying.
Anyway, there was no way of telling what was true and what was not, and Damian stood there, thinking about his next moves. He was safe there, as almost no one knew the location of the hidden shack, but the best course of action would leave the area as fast as possible.