BOOK REVIEW : A Mystery That’s Really About Families--and New Orleans Itself : BLUE BAYOU <i> by Dick Lochte</i> ; Simon & Schuster $20; 278 pages

One of the most memorable passages in Dick Lochte’s mystery novel “Blue Bayou” occurs at the end of a scene in which a leading character meets his maker. The last few lines are told from the victim’s point of view, just after he has been knocked into semi-consciousness and the killer has begun to arrange his body into a position that implies suicide. “There was the sensation of being moved,” writes Lochte. “The tiles felt cool. He’d had them imported from Spain. He heard the running water. Someone was drawing a bath.”

The passage stands out because it veers toward the hard-boiled tradition of detective fiction, in contrast to the rest of the book.

Lochte, author of “Sleeping Dog” and “Laughing Dog,” doesn’t write prose that draws attention to itself; it serves his characters rather than their creator, which makes “Blue Bayou” more ambitious than the typical mystery. That can be a mixed blessing--Lochte isn’t interested in creating drama or easy laughs--but what Lochte does deliver is an engaging cast.

Although a few of the characters in this Louisiana-based mystery seem to have walked straight off a television private eye show, the principals have been drawn with care and sympathy. The real star of the book, however, may be New Orleans itself, for there are few pages in this book that aren’t infused with its tolerant, colorful, spontaneous culture.

We meet Terry Manion, Lochte’s detective, at a spa outside New Orleans where he’s been drying out since he was turned into a drug addict in Los Angeles by a gang of killers. (That case is told in “Laughing Dog,” which stars Lochte’s L.A. detective, Leo Bloodworth, and his 15-year-old sidekick.)

Before Manion is released from the spa, a number of odd things happen: An orderly snoops around his room; an old parochial school classmate, now policeman Eben Munn, shows up to interview Manion about the L.A. case; a best-selling novelist volunteers to become Manion’s post-addiction sponsor. Manion soon discovers that these events are intimately connected, the link being a young mobster, Reevie Benedetto, who wants to displace his father as the king of Louisiana crime.

Manion is drawn into the situation when he learns upon leaving the spa that his professional mentor, J. J. Legendre, has apparently committed suicide. Manion simply can’t believe that Legendre would kill himself. However, he soon figures out that Legendre, who took care of Manion’s agency during his absence, had stumbled on a case that took him too close to some major, unpleasant truths.

Although Manion and Munn have separate agendas, they form an uneasy alliance in an attempt to solve what turns out to be a string of apparent suicides. Munn, a good old boy, is constantly breaking police procedures and trying to drag Manion back into New Orleans’ wild night life. Manion, for his part, has to answer to Nadia Wells, a motherly former madam who runs the agency that employed Legendre and got Manion into the detective business in the first place.

The interplay between Manion and Munn is the best part of the book, Munn always ready to say things like “I have seen Manion under pressure. Sweating under the aluminum ruler of Sister Veronica.”

Lochte has given “Blue Bayou” a dense, complicated plot, the numerous killings uncovered in the course of the book eventually being traced to perhaps half a dozen people--maybe more; it’s difficult to keep track. The identity of the one professional killer, named Croaker, is the source of the novel’s only tension, but “Blue Bayou” isn’t intended to be suspenseful. Lochte tells us straight out, in the book’s prologue, that Legendre isn’t a suicide. It is, rather, about relationships, among friends and by blood, and the things they make people do.

“In this part of the country,” says Manion toward the end of the book, “it’s always about families, isn’t it?”

Manion’s observation is hardly restricted to Louisiana, but his choice of locale makes the relationships between his characters all the more compelling.