Ten-year-old Leo's future and the fate of the extraordinary Whippet Hotel, where his father is the maintenance man, are at stake when a series of cryptic boxes leads Leo to hidden floors, strange puzzles, and unexpected alliances.

At Greenglass House, a smuggler's inn, twelve-year-old Milo, the innkeepers' adopted son, plans to spend his winter holidays relaxing but soon guests are arriving with strange stories about the house sending Milo and Meddy, the cook's daughter, on an adventure.

Six-year-old Eloise loves to take a bath, which is bad news for Mr. Salomone and the elegant people gathering below in the Plaza's Grand Ball Room for the charity event of the season, a Masked Ball.

While visiting Aunt Molly at a fancy downtown hotel, Cam uses her photographic memory to help one of the guests find her stolen luggage and pet cat, and to catch the thief.

While staying at an eighteenth-century inn in Vermont, the Boxcar children become curious about the mysterious "accidents" that keep plaguing the owners.

"Leo has explored the zany, wonderful Whippet Hotel from basement to top floor, with trains, flying goats, and mazes (among other things) in between. But even Leo doesn't know every secret of the Whippet - and when he discovers that there's more beneath the hotel than he'd thought, it doesn't take long for more adventures to unfold!"--Dust jacket.

Geronimo tries to enjoy his seaside vacation even though his hotel is dilapidated.

"P.T. and Gloria need a great plan to ensure the Wonderland can beat a slick new attraction in the "Unsung Fun In The Sun" contest." --

Elizabeth, eleven, spends Christmas break at Winterhouse hotel under strange circumstances, where she discovers that she has magic, and her love of puzzles helps her solve a mystery.

Five murder suspects are invited to the haunted Barclay Hotel for a weekend getaway, and it is up to twelve-year-old JJ and eleven-year-old Penny--and a lonely ghost--to figure out who committed the crime.