There are coincidental echoes of “Running on...

There are coincidental echoes of “Running on Empty” in John Katzenbach’s Day of Reckoning. Two ‘60s radicals, who fled undetected from a botched bank robbery in which two of their pals died, are not on the lam from the FBI as in the movie but have settled into upper-middle-class yuppie heaven in Massachusetts. He’s a banker; she makes a bundle selling exurban real estate.

Back into their lives bursts the leader of their revolutionary cell, a ferocious woman code-named Tanya (which was also Patty Hearst’s underground name, as the characters note). Tanya’s resentments have been sharpened by 18 years of hard time in prison. She never ratted on the couple but never forgave them either.

Now, accompanied by a feckless but lethal pair of sidekicks, one from the old days, she kidnaps the couple’s young son and his grandfather and begins a taunting game of extortion.

Katzenbach, who launched his career with “In the Heat of the Summer,” a Miami-set cat-and-mouse struggle between a reporter and a killer, does not probe deeply into any of the characters or the past. (The couple appear to have been dilettantes who got in over their heads.) But the scenes in captivity between the boy and his grandfather are strongly appealing, and the story rushes headlong to a spectacular finale.

By a curious congruence, several of the month’s mysteries center on archeology in one guise or another. The best of the lot is probably Black Sand by William J. Caunitz, who also wrote the best-selling “One Police Plaza.” The black sand of the title was used by the ancient Greeks to preserve manuscripts, in particular an annotated copy of the “Iliad” owned by Alexander the Great.

The manuscript (if indeed, it exists; it is a perfect Hitchcock MacGuffin or all-purpose quarry) is central to a plot involving smuggled antiquities of inestimable value.

The book is an expert police procedural set mostly in New York and involving the cooperation of a Greek-American NYPD detective named Teddy Lucas and an Athens detective, Andreas Vassos, whose wife and child were killed by the smugglers and who has come to Manhattan on a mixed mission of detection and revenge. The real villains are highly placed but not beyond reach. “Black Sand” is the very model of the quick, sleek, commercial thriller.

Curses by Aaron Elkins places archeology where it belongs, at the site of a dig, this one in Yucatan. Elkins’ sleuth, a physical anthropologist named Gideon Oliver who finds clues in skeletons, almost becomes one when a Mayan tomb collapses.

What we have here is either an ancient curse or present evil rooted in greed. Only one guess per customer. The grail is again an ancient document, a codex or manuscript setting forth age-old Mayan beliefs. Elkins papers his brisk, brief plot with a good deal of authentic-sounding lore.

Like his hero, James E. Martin has a police background, and it shows in the believability of the cops and robbers in The Mercy Trap. Gil Disbro is yet another ex-cop turned not very affluent private eye in Cleveland. He mostly chases skippees for a bail bondsman. Then he gets a real case, to locate the birth mother of an adopted woman who desperately needs a kidney transplant. Never did the probing of the past overturn more cans of worms or more wormy characters. High marks to Martin for a plot that is clever and intricate but not impossibly beyond belief.

The author recites street names in Cleveland and surrounding territory the way Raymond Chandler used to recite litanies on Los Angeles. The effect is not quite the same in Ohio, but the confident sense of place gives a firm footing to Martin’s story.

The population of female private investigators continues to grow in fiction, whatever is happening in real life. The tough but feminine Delilah West of Orange County is one of the grittiest. In Maxine O’Callaghan’s Hit and Run, a string of foul luck has reduced Delilah to a sleeping bag on the floor of an office on which she may or may not be able to make the next rent payment.

She’s nearly run down by a hit-and-run driver who has apparently hit and killed an old man across the street. It’s characteristic of her luck that for her first case in weeks she’s retained by the driver’s mother to prove her son didn’t kill the old man after all. He didn’t, either, as Delilah quickly concludes. But who did, and why, and how it relates to a sweet-faced grandmother-type with the appetites and habits of a riled rattlesnake all becomes clear in record time.

West takes beatings that would discourage Mike Hammer, but like old Mike, she gives at least as good as she gets and is not to be trifled with. O’Callaghan, who lives in Mission Viejo, has her own sense of place, and her plot is the more compelling because it is more like the next page of a police blotter than a blue-sky invention of fantastic size.

John Byrne Cooke’s South of the Border is not so much a mystery as the fictional solution to a mystery: whatever really happened to Butch Cassidy. Did the mowing-down at the end of the movie not really happen or, if it did, did he survive? His sister said he visited the folks in Utah in 1925, well after the supposed unpleasantness in South America. A scholar argued, for a while at least, that Butch lived in Spokane under the name Phillips until he died in 1937.

In an elaborate melding of careful research and lively invention, Cooke brings Butch back alive for a last caper, success in love and a happy ending. The fictional voice is of the real cowboy author Charles Siringo, and Pancho Villa plays a large role.

Not least of Cooke’s achievements is a prose style, dignified and even slightly stiff, that seems exactly the way a largely self-taught but well-read ex-cowboy might write if he turned his hand to the making of memoirs.

DAY OF RECKONING by John Katzenbach (G.P. Putnam’s Sons: $19.95; 368 pp.) BLACK SAND by William J. Caunitz (Crown: $18.95; 339 pp.) CURSES by Aaron Elkins (Mysterious Press: $15.95; 208 pp.) HIT AND RUN by Maxine O’Callaghan S. Martin’s: $14.95; 192 pp.) THE MERCY TRAP by James E. Martin (G.P. Putnam’s Sons: $16.95; 240 pp.) SOUTH OF THE BORDER by John Byrne Cooke (Bantam: $17.95; 336 pp.)