Hot-air balloon enthusiast Margaret Barlow returns to her alma mater, the snobby Brides Hall, to check up on her granddaughter after the death of a scholarship student, Mary Hughes, who was found hanged (murder? suicide?) in the bell tower. Margaret is convinced that Mary's death was murder, and handsome Lt. Dominic prevails upon her to snoop around. She discovers: that her old school-chum and current headmistress, Ellen Nornay, is newly glamorous and now rich; the school treasurer has been fiddling with the books; the student leader is a bully; and Mary may have been killed because of a picture she took and a tape she recorded while bird-watching on neighboring property. Then the school housekeeper is bisected by a descending elevator, and Margaret herself is attacked in a storage room--but recovers in time for the annual grudge race (on the Chesapeake) against Saint Hubert's--during which the guilty party is fortuitously jostled overboard. Excellent depiction of boarding-school life, and Margaret, immensely toned down after Murder on Martha's Vineyard, is a likable, middle-aged sleuth--though the plot she perambulates through is still silly and implausible.