There's something undeniably appealing about Keating's Mrs. Craggs: a no-nonsense charwoman who matter-of-factly sees the Truth while her ""betters"" fuss blindly. But most of these 18 mini-stories are so wispy and/or strained that even Mrs. C.'s brusque proletarian charms, malapropisms and all, soon wear thin. Best of the murder-puzzles is ""Caught and Bowled, Mrs. Craggs,"" with lots of well-observed posturing at the Marylebone Cricket Club. Much less satisfying are the far-fetched killings at the House of Lords and the British Museum. And many of the stories feature such low-key crimes--a minor scam at a landmark commission, church-donation theft, the theft of obituaries-in-draft from a newspaper--that there's not enough substance to sustain even a lighthearted, ten-page story. Frail mystery tales, then--but undemanding fanciers of droll English comedy may enjoy Mrs. C.'s cockney bluntness, the fake gentility of her colleague Mrs. Milhorne (who is overexposed in a slew of cutesy introductions), and the mild satire of British institutions.