Horton Halfpott: Or, the Fiendish Mystery of Smugwick Manor — Tom Angleberger

There are so many exciting things in this book -- a Stolen Diamond, snooping stable boys, a famous detective, love, pickle eclairs -- that it really does seem a shame to begin with ladies' underwear . . .

IT ALL STARTS WHEN M'LADY LUGGERTUCK LOOSENS her corset. As a result of "the loosening" all the strict rules around Smugwick Manor are abandoned. Shelves go undusted! Cake is eaten! Lunch is lukewarm! Then, when the precious family heirloom, the Luggertuck Lump (quite literally a lump), goes missing, the Cuggertucks search for someone to blame. Could the thief really be Horton Halfpott, the good-natured but lowly kitchen boy who can't tell a lie?