Peters can be counted on for fluid and literate readability--even when, as here, she slips into archness, with sentimentally overdrawn English-village ""characters"" and more than a hint of gothic romance. The bucolic setting is the valley of Middlehope, where newcomer Arthur Rainbow, power-loving antiques dealer, has just bought and refurbished the largest house around; and, through his newly-grabbed post as church organist, he's proceeding to refurbish the church music as well. This sits poorly with the choirboys (who have names like Toffee Bill and Spuggy) and with Bossie, their leader, a 13-year-old of numbing precocity who has a plan to dislodge the hated Rainbow--a plan that involves a scrap of supposedly ancient parchment found at the site of a local abbey undergoing restoration. And all this provides the motivation (slim) for Rainbow's murder, which is investigated by the particularly dim Superintendent Felse and by the interminably indomitable Bossie (who's saved from the villain in a boys'-magazine climax). A treat whenever medievalist Peters is describing the abbey and its history; rather thin and precious most everywhere else.