Dancing on an Echo. Mansion of Ghosts and Gold, #2

"I pondered the thoughts of that crow as he heard his caw returned by a comrade, " wrote Uncle Proctor. "Did his mind play a clever game and judge it to be merely an echo?"The saga continues for the Banyon family after their adventures in Falling into the Distance. Andy and Annabeth find an odd map mixed in with many old books from the departed Uncle Proctor. Before they can study it, the phone cries out with a call from the executrix of the estate.
The entire family is called back to the esteemed maestro's dark and brooding mansion. The kids quickly match the map to a forgotten area of the third floor, and they locate another of Proctor's journals, then a secret stairway leading to an even more secret attic. With Barkley helping, the kids recreate an experiment that led to some terror for Uncle Proctor, and they meet what had caused his fright.
The mysteries swirling around Proctor like a tumultuous murder of crows seem to have no end. They all hope there's no end to his stash of shiny gold coins too.