Coincidence, not consistency, is the hobgoblin of little murder mysteries.

"Mr. Right," a devious and delicious first novel, is above such trivial concerns. While enormous coincidences clang throughout, the characters dismiss them with a literate, insider's humor. Faced with the most thundering example of prurient Providence, the "hero" shrugs cheerfully: "He would, he resolved, give the novels of Thomas Hardy a second chance."

"Mr. Right" begins as a study of several distinct relationships -- Lida and her best friend Diana; Lida and Duvivier, the author of a series of erotic thrillers; Diana and her newfound lover Allen; Allen and his academic colleague Riley -- and inexorably develops into a diagram of a single, pentangular affair, each character tied to the others. It is a singularly subtle adaptation of the tightening noose image, and a brilliant exploration of the random element in violence.

Lida is 35, restless, reckless, a closet romantic frustrated by the bedhopping which exposes her to unimaginative men. She teaches literature (with a likeable iconoclasm) in a small, innercity community college allong with 43-year-old Diana, a divorced Jane Austen specialist.

Duvivier is only one of three psuedonyms used by an expatriate writer who believes his real identity has been buried long ago, along with the corpse of the murdered student who spent her last night with him. When Lida strikes up a correspondence with the elusive Duvivier -- peeling away the disguises one by one -- he counters by initiating an affair as the prelude to silencing her. As the two mysteries -- of Duvivier's identity and of the student's murder -- unravel, they are revealed as two ends of the same rope.

Like most mysteries, it sounds prosaic in skeletal form; but Banks' writing supplies the flash and energy that illuminate "Mr. Right." The chapters, often a single page long, and the even briefer "verses" of these chapters slice together like playing cards in mid-shuffle. Lida, Duvivier, Diana, Allen, Riley, Lida, Duvivier, Diana... the faces spin until the reader is seduced into just the assumptions the author desires.

Banks' ear for dialogue -- a subject on which Duvivier her alter-author, discourses knowledgably -- is shrewd; she provides Lida with a defiant, smart-aleck tone through which glimmers a wistfulness and a gallant resilience. Lida is also blessed with the off-center stream of consciousness of a "Doonesbury" caricature:

"Lida stared at her feet, wondering if the tennis shoes she was wearing made her look like a housewife.

"'Are you a lesbian?' he asked."

"'Why? Do they wear tennis shoes?'"

Duvivier, on the other hand, has an air of dreamy unreality; not a schizophrenic but uncertain. His relationship with the eminently earthy Lida serves to anchor Duvivier more strongly to real life, however, and he begins to separate his past from his own fiction.

Diana, frankly, is a neglected creation only half-realized and dismissed as a necessary pawn in the play. So are Allen and Riley, all three being sublimated to the electricity between Lida and Duvivier.

Reading "Mr. Right" is a little like seeing Robert Altman's "Nashville" -- the clues are so smoothly mixed into the action that they're virtually invisible, but after the solution they stand out like neon arrows. A swift second reading is worthwhile just to admire Bank's wiliness.