Here is the text from The Under-Galleries:
And here, Wizard's Trove:THE UNDER‐GALLERIES ‐ Dark‐hold [ ] (Under‐deeps) (R)
[MP: 3; opponent draws/you draw: 4/1]
Adjacent Sites: Any site in Ûdun (0), The Under‐courts (4), The Sulfur‐deeps (8)
Playable: Items (minor, major, greater)
Automatic‐attacks (2): (1st) Trolls ‐ 4 strikes with 9 prowess; (2nd) Opponent may play as an automatic‐attack one non‐ unique
hazard creature from his hand normally keyed to Shadow‐holds [ ].
Special: Stolen Knowledge. When Under‐galleries would be placed in your discard pile, place it in your marshalling points pile
instead for 3 marshalling points ‐ this card is considered stored.
WIZARDʹS TROVE ‐ Permanent‐event (R)
[SP: 1]
You may play The White Tree at one of your Wizardhavens [ ] if Sapling of the White Tree is stored there. Place Wizardʹs Trove
with The White Tree ‐ which is worth full marshalling points. Your Wizardhaven [ ] becomes protected. Ignore the text of The
White Tree.
Alternatively, you may store one miscellaneous marshalling point card at one of your Wizardhavens [ ]. Any reference to the site
where the card can normally be stored are transferred instead to the Wizardhaven [ ]. Place Wizardʹs Trove with the stored card
‐ which is worth full marshalling points.
It seems to me that it's not possible, but I wanted to make sure it isn't...