The Drackenmire Ghouls' Treasure Trickery

Jeeves Baldwin is hired as butler/ driver/ representative for the Drackenmire Estate family of assorted ghoul types and reformed vampires. He must sell jewels “acquired” by the family over the centuries and now in the mansion’s treasure room to pay the bills including his own salary.
Neighbor Villana DeCrewel has a big estate but little income so she is always looking for money any way she can get it. She parties with art thief and collector Seymour Scovar and separately with local mid-level mobster and collector of unusual jewelry, Giorgio Xylode.
Xylode’s employee jeweler Kirby Kirbey, appraises an antique jewelry piece for Jeeves and feels sure that must be part of a treasure trove. He snoops and ends up breaking into the estate’s treasure room and stealing the two chests of jewels he finds there.
Jeeves and the Ghouls figure out who stole the treasure and who has it now - as Xylode takes it all from Kirbey, only to have top mob boss Carlos Sabatini take it all for himself. Jeeves (and the unseen ghoul family members) team up with Scovar and DeCrewel, for a daring cat burglar raid to try to remove all the jewels from Sabatini’s inner sanctum. They survive several near miss but get away intact. When they check their holdings though Scovar, DeCrewel, and Sabatini all find they have only cheap costume jewelry and no way to know for sure if that was all they ever had.