Charmingly old-fashioned but full of vigor, three tales about spry mouse couple Mr. and Mrs. Nutmouse offer humor and adventure. Tumtum and Nutmeg (fond spousal nicknames) live in “a big, rambling house with a ballroom, and a billiards room, and a banqueting room, and a butler’s room” nestled secretly in a hidden broom cupboard of a cottage. In the cottage live Arthur and Lucy, human children whom Nutmeg and Tumtum clandestinely care for, explaining their helpful deeds by claiming to be a (single) fairy. The Nutmouses prefer peace and quiet, but the children’s surly, musophobic Aunt Ivy strives to poison them until their wild and hilarious scheme expels her. That done, pompous General Marchmouse, a war hero given to “foolish heroics,” embroils them in two more escapades, one involving gerbils and ballerinas, the other pirates. Bearn’s neat, understated prose never missteps, while the small-scale domesticity nods to various classics including The Wind in the Willows and The Borrowers. Sweet but never saccharine—and how often do rescues involve mice on pogo sticks? (Fantasy. 6-9)