Fremlin, whose novels often ramble on diffusely, is at her best in short stories--and this baker's dozen includes a few sharp, disturbing items along with the crisp, smooth, nicely turned ones. The title piece, brief and horrific, zeroes in on a mercy-killing gone wrong. ""A Case of Maximum Need"" gives a truly jolting windup to an already-compelling piece about an 87-year-old woman and the social worker who insists (over all refusals) that the old lady needs a telephone. Likewise, ""The Holiday"" centers on a widow with a quirk--she hates holidays--that turns into a murder-case misunderstanding. And the powerful passions and kinks hiding behind sweet, elderly faces also figure in ""The Bonus Years"" (two con-lady widows on a cruise) and ""High Dive"" (a nice non-mystery piece about a 76-year-old man's determination to impress his 65-year-old wife). Other stories have more standard themes: wife-murder, husband-murder, frame-ups and angry mistresses. But, throughout, Fremlin's short-fiction--while not as original or stylish as Ruth Rendell's--is brisk, readable, and quite frequently creepy.