MYSTERY:  Nemesis--one who inflicts retribution or justice--seems an odd name for an elderly, rather frail woman. But not if that old lady is the formidable Miss Jane Marple. Soon after the death of financier Rafiel, the man who'd called her by that name, Miss Marple is summoned by his solicitors. A letter from the grave sends her on a baffling quest--to investigate an unidentified crime.