The Bromeliad Trilogy (Truckers, Diggers, Wings)

In a world whose seasons are defined by Christmas sales and Spring Fashions, hundreds of tiny nomes live in the corners and crannies of a human-run department store. They have made their homes beneath the floorboards for generations and no longer remember - or even believe in - life beyond the Store walls. Until the day a small band of nomes arrives at the Store from the Outside. Led by a young nome named Masklin, the Outsiders carry a mysterious black box (called the Thing), and they deliver devastating news: In twenty-one days, the Store will be destroyed. Now all the nomes must learn to work together, and they must learn to think - and to think BIG. Part satire, part parable, and part adventure story par excellence, master storyteller Terry Pratchett's engaging trilogy traces the nomes' flight and search for safety, a search that leads them to discover their own astonishing origins and takes them beyond their wildest dreams.