 What is the "thing"?
The golden Moon and the silver ship, symbols of greed. All my great-grandfathers have it. I was bent double, but I got from the floor to the chair and found my notebook and orb-point in my hands. They told everything I needed to know to become the most powerful man in the Solar Federation. I remembered that he was somebody very important whose name and work I had once known, even if now I knew him only as Doc. I was a man , of course, not an alien like a Martian. I surrounded it like an ameba, almost in a single movement of my jaws. Everybody has a name, and I knew if I went off somewhere quiet and thought about it, mine would come to me.
 An agent of time travel.
 A state of pure thought.  A book that doesn't exist.  A vehicle to find coffee.  An agent of time travel.