The Betrayal of the Stars
Jameson was a dear friend of Nick’s until his semi-recent passing. Nick met Jameson when he was rather old, in human reckoning, and the two were fast friends until his passing. Upon his death, he bequeathed a riddle to Nick that he has yet to unravel, but which haunts him daily.
(Feel free to edit or add to this as needed Nick, I included it here because I wanted to be sure to remember it.)