Jane Langton's pen-and-ink illustrations, which decorate the pages of her books about retired Massachusetts detective Homer Kelly and his historian wife Mary, are as apparently simple--and deliciously deceptive--as her words. Even if your mystery tastes run to the tough and hard, you'll have trouble avoiding the warmth, sharp wit, and clever detection that animate this series. "Homer Kelly had been Mary's husband for a long time," begins a typical Langton paragraph. "He was a big man with a coarse gray beard and a rough head of hair like the thick fur of a dog. His impulsive enthusiasms had often led him into absurdities in the past, but half a lifetime with a sensible wife had mellowed him a little. So had his experience with violent criminals." It's art that gets Homer and Mary involved in their 13th adventure, when an 8-year-old boy with Down syndrome is found murdered near a wall that Mary's niece has been illustrating with characters from fairy tales. The missing, abused wife of a nasty property developer is also part of the mystery, which the Kellys unravel in a suspenseful and thoroughly plausible manner. Other Kelly outings available in paperback include The Dante Game, Dark Nantucket Noon, Dead as a Dodo, Divine Inspiration, Emily Dickinson Is Dead, God in Concord, Good and Dead, The Memorial Hall Murder, and Murder at the Gardner. --Dick Adler