The dust never really settles in a haunted priory, and Prudence Honeysett learns that valuable lesson all too quickly. An idyllic stretch of quiet passes following the disaster in the priory's garden, and normalcy hints at a return with the final stages of the priory grounds' beautification and the upgrading of the interior with newly purchased antiques and - well - "antiques".
Trouble once again brews when Prudence and Frederick go on a shopping spree, and they unwittingly purchase an item that's apparently haunted by a dead letch. But ghostly warnings tend to come in riddles, and a frenzied search for the mystery item turns into yet another dip in the waters of frayed nerves, late night tipples, and terrified young servants being harassed by the image of a lascivious dead man in the mirror.
In the meantime, Freddy gets whisked off to help a neighboring French gentleman whose Medieval hall is haunted by a lost servant who, literally, can't find her way around the maze of passageways and rooms. Freddy's attention is now divided, leaving Prudence to sort out priory troubles with a bit of help from an overly zealous friend.
Throw in a generous dose of a young man's clumsy sexual awakening, a visiting dandy who's also a purveyor of literary smut, and a servant suddenly allowed a note-book into which he can share his energetic accounts (and marvelous art) of the madness within St. Grimald priory's walls, and readers are in for another madcap epistolary adventure over tea.