Mary Norton

With the powers they acquire from a spinster who is studying to be a witch, three English children have a series of exciting and perilous adventures traveling on a flying bed that takes them to a London police station, a tropical island, and back in time to the seventeenth century.

In a secret world hidden beneath the floorboards, little people called Borrowers live quietly among us. But when tenacious and tiny Arrietty is discovered by Shawn, a human boy, their secret and forbidden friendship blossoms into an extraordinary adventure.