Includes a Naked Bad Guy

When Tucson teenagers kayak the bayou, only private investigator Del Shannon is there to save the day

Slim and sexy, blond private investigator Del Shannon is back and copping her standard pose: modified police stance, glaring over her Baby Eagle, popping off rounds dead center at targets in Scotty's Indoor Shooting Range.

She's about to have an improbable ... make that implausible ... adventure.

Purgatory Key is Tucsonan Darrell James's third and final Del Shannon mystery. In 2011's Nazareth Child, Shannon ventured into the bizarre world of Appalachian religious fanaticism. In 2012's Sonora Crossing, she took on a superstitious drug lord in Mexico. In Purgatory Key, it's bad guys and Cajuns and tigers (oh my!) in the swamps of Louisiana.

The novel opens with two teenagers from Tucson kayaking through a twisting bayou to trespass on a private cypress- and Spanish moss-entangled island. They promptly encounter a Cajun, the two bad guys (one of them naked), and—yes—two pet white tigers, and are grabbed to be held for ransom. When the grandfather of one of the girls—back in Tucson—gets the ransom demand, he calls on Shannon to deliver the money.

In a remote spot in the Catalinas, with the money in her Wrangler, a haboob on the way and the stupider of the bad guys suddenly feeling horny, Shannon is forced to defend herself ... which she does with a bullet to the guy's heart. That leaves her safe, but it cuts off access to the kidnappers and the girls. She has, she realizes, screwed up. With only the dead man's cellphone and a strip club matchbook from his pockets, Shannon is left with few clues.

Shannon repeatedly reminds herself that "there are no coincidences, just incidents that coincide." And some incidents are about to coincide.

That very evening, in fact, while trying to drown her screw-up, she runs into old boyfriend—and federal agent—Frank Falconet, who just happens to be searching for a dangerous fugitive. After a refreshing reunion, they track down the matchbook club location, which, coincidentally, is in the very area of Louisiana where Falconet's fugitive was last seen. So Shannon and Falconet head for the bayous together.

Togetherness with Falconet works for Shannon, who's been pretty lonely. Raised by an abusive father, in Nazareth Child she went in search of her mother. She met Frank Falconet when he was leading a federal investigation into the religious cult into which her mother had disappeared. When they collaborated professionally and became lovers, Shannon had the chance to stay with him, but she passed it up. In the intervening two years, she has had one-night stands and no-strings relationships, but essentially she's unhappily on her own. And—oddly—since she's a tough, smart, 30-something contemporary woman—she actually longs for a "knight in shining armor."

As he did in both previous Shannon novels, James creates an interesting, exotic setting for the action. An overgrown island surrounded by swamp and sea, on which an eccentric millionaire had built a mansion with statues, currently inhabited by dangerous animals and a recluse who is regularly serviced by a fugitive thought to be dead, is an ideal place to maroon two teenagers. When Shannon finally gets there, the atmosphere is suitably oppressive and threatening.

The plot, though, is less convincing. Once the action in Purgatory Key gets moving, the reader is inclined to stay with the book, but the opening chapter, with the Arizona girls paddling through a Louisiana swamp on a yet-undisclosed mission feels unmotivated and implausible. When the purpose of the mission is revealed (I won't give it away, but think treasure) it seems no more plausible.

The narrator's point of view also impacts character development. Here it constantly shifts. Admittedly, that allows the reader to follow the thoughts and actions of not only Shannon, but also of the individual kidnappers, the individual girls, Falconet, Shannon's boss, the grande dame of the island, and the Cajun tiger-minder. That simplifies spinning out the story, but it also has the unfortunate effect of distancing the reader from the central character and impeding both character development and the establishment of sympathy one would normally have for her. We don't know much more about Shannon by the end of this book than we did at the beginning. She does undergo some change, but we're told about—not shown—it.

There's a quirky mystery on the island that's satisfying. And irony in the book title? The island itself is called Terrebonne (Good Earth) Key. Good Earth is more promising than purgatory, and Shannon just might find something there.