We found a cave with a glary beast and my grandfather who left after a drought to find answers to save the family. He sacrificed "seeing his family for the rest of his life" and was blinded, he guards the cave and cannot leave.
Grandfather gave a full journal to pass on to our family.
The entity told us we can trade someone to his post or teach it how to find illithids to get him back.
It gave us some information based on hoping to pin us against illithids at no cost to it.