Whodunits Keep the Pages Turning

SHELLEY'S HEART

By Charles McCarry

Random House

556 pp., $23.

DEATH OF A NAG

By M.C. Beaton

Mysterious Press

216 pp., $18.95

SAUCE FOR THE GOOSE

By Robert Campbell

Mysterious Press

229 pp., $18.95

BLACK OUT

By John Lawton

Viking

342 pp., $22.95

BURNING ANGEL

By James Lee Burke

Hyperion

340 pp., $22.95

RAINBOW'S END

By Martha Grimes

Alfred A. Knopf

384 pp., $23.

THE popularity of mysteries is ever-increasing, and you don't have to be a Marple, Morse, or Millhone to understand why. The good guy wins, the bad guy gets caught, the mayhem stops, and the evil deed is dealt with.

In the ''real'' world, television news is filled with too much crime and too little punishment. But unlike reality, a good murder mystery usually provides a solution to a crime. It fills a basic need. It provides a sense of order and justice.

We might not be able to agree on what deserves a PG-13 rating, but in mysteries, right and wrong are clearly defined (at least by the protagonist's standards). They satisfy an inner desire for order, justice, and sometimes - let's be honest - retribution. It's nothing new, of course. Our historical counterparts had morality plays. A quick study of the history of the mystery reveals that as a genre it is particularly adept at mirroring the times. Current mysteries, for example, seem to highlight women in every guise, from sullen and single to suburban and snappy, while society, too, branches out beyond traditional female stereotypes.

But let's not get too serious. The best mysteries also offer sheer pleasure, with strong characters we come to regard as friends, settings so vivid we know we've been there, and tricky plots.

Here are some of the newest offerings.

''Shelley's Heart,'' by Charles McCarry is not only the best political thriller to come along in years, it's one of the best novels I've read in years. And joy of joys - at least for this reader, until now unfamiliar with McCarry - ''Shelley's Heart'' is the eighth in a series of novels featuring one family.

The plot of ''Shelley's Heart'' revolves around what happens after a new American president is accused of stealing votes to win. Political junkies will delight in the utterly believable machinations that ensue.

The book's strength comes from its people more than its insider politics. From a sanctimonious Supreme Court Justice to an endearingly honest but often tipsy Speaker of the House, McCarry has created characters so real that you feel deprived of actual relationships when you finish the book.

The plot's intricacies validate the complex nature of its characters; layer upon layer of duplicity, scheming, and espionage. The technical gadget stuff is fascinating, and, according to an author's note (among other careers, McCarry was a CIA officer for 10 years), already in existence. Intrigue is expertly woven in, and even the shrewdest reader will be held until the last turn of the page.

''Death of a Nag,'' by M.C. Beaton, continues a usually light and charming series featuring that lazy and laconic lad from Lochdubh, Sergeant Hamish Macbeth.

Macbeth takes on a darker tone here, and not with positive results. On holiday, he gets involved in a murder among his boarding-house mates. The consequences are both dire and ironic. Yet, the mood is too heavy to support such a light cast and plot, and the sparks between Hamish and the lovely Priscilla (absent in England for this book) are sorely missed.

''Sauce for the Goose,'' by Robert Campbell, serves up Jimmy Flannery, husband, father, sewer inspector, and Democratic committeeman for Chicago's 27th Ward. He is likeable the minute he opens his yap. ''Like every new father that ever lived, I feel a little lost around the house.... A baby changes your life more than all the career plans and ideas for the future you can imagine. I mean it ain't like it's a dog that you can tell to go lay down in the corner.''

Jimmy, making his ninth appearance, is taking night classes in both grammar and political science. His classmates who involve him in murder. His local connections being a lot stronger than his grammar, Jimmy gets help from his usual charming cast of friends and family, all refreshing in their unabashed ethnic ties and bonds.

Campbell, who also writes the wonderful ''La-La Land'' series, is that rare breed of writer who makes it all look easy.

''Black Out,'' John Lawton's first novel, set in London during World War II, is so polished it's going to cause a lot of despair among the manuscript-in-the-drawer crowd. And it should.

When children playing in rubble find a severed limb, Detective Sergeant Frederick Troy initially thinks it's the result of the war: It is London in 1944, after all. But Troy is too shrewd to go meekly where he's led, and soon he's involved in labyrinthine coverups. From working girls to spoiled aristocrats, the cast is peopled by real, complicated characters. This is a stunning debut.

''Burning Angel'' by James Lee Burke brings Louisiana detective Dave Robicheaux back on solid ground (well, as solid as it gets down there) after a few recent overwritten episodes. When some sharecroppers are being forced off land they've ''owned'' for more than a century, Dave's sleuthing gets him mixed up with mobsters and other shady types. As usual, the strongest pull of this series is Burke's mastery in evoking the steamy mood of the place, from the sting of workers' sweat to the smells of what's cooking in their pots.

In ''Rainbow's End'' by Martha Grimes, Richard Jury travels from England to Santa Fe, N.M., looking for a link among three murders. Along the way he seems bewildered, as readers of this muddled mystery will be. The scenes featuring ex-Earl Melrose Plant and Sergeant Wigging still sparkle, as do those with the pub regulars. But Martha Grimes of late lacks the control and style with which she dazzled so many fans in her earliest book.