THREE TERRIBLE TRINS

King-Smith (Sophie in the Saddle, 1994, etc.) parodies human behavior in another of his animal fantasies. In the house of irascible Farmer Budge, mouse society is literally stratified. The thrice-widowed Mrs. Gray is an exception: She has not only been married to another aristocratic Attic but also to one of the comfortable Ups and, most recently, to a plebeian Down. When portly Mr. Gray is eaten and she's left with three tiny sons, she vows to train them as "guerrilla fighters in the cause of mousedom." And with her urging, plus the help of a hearty Cellarmouse, who also wins the pretty widow and moves into the west wing of her elegant chair in the attic, the "trins" eventually oust a half-dozen cats from their domain. King-Smith's wit is unabated; his sharp characterizations, including that of old Mrs. Budge, who slips treats to the mice her husband abhors, and such details as the "M1" that's the principle mouse thoroughfare between floors, are a delight. The class divisions that are the story's basis are peculiarly British, but they aren't liable to confuse anyone. A lively comic adventure. (Fiction. 8-12)