Interrogating a Ghostly Warder

An interesting wrinkle in the concept of Ghostly Warder has appeared in our saga.

Our Ex Misc magus has a Ghostly Warder - "Gramps" who apparently a Hedge Wizard ancestor that wants his descendant to make achieve some magical goal, that the former wizard is extremely focused on, but rather vague about.
We have just found out that the Ex Misc wizard's relatives, those with any magical ability and descended from the same ancient Hedge Wizard also have the Ghostly Warder Virtue. Specifically the same Ghostly Warder "Gramps". At least 2 NPCs currently have access to "Gramps", at the same time as our Ex Misc magus.

The SG hinted they all reflect an aspect of a greater power.
Anybody have suggestions as to what this may be. I don't currently have access to the Realms of Power books, or Hedge Magic RE, but I suppose this is a Genius Locii, or perhaps a wizard that has Ascended?

Thing is, "Gramps" has apparently dropped the name Davnalleus, in relation to something else.
My character really wants to interrogate this "ghost" or whatever it is an aspect of, for further info, but my character does not have Second Sight.
Any suggestions on how to interrogate "Gramps"?

InMe with decent Penetration should do fine unless it is R: Eye, shouldn't it: you might think about ArM5 p.149 Posing the Silent Question with R: Touch or R: Voice. Tunnel spells can be useful here to change R: Eye spells accordingly.
I'd advise against ArM5 p.152 Coerce the Spirits of the Night, not to antagonise overly your Ghostly Warder.