The Pearl Diver, a thoughtful mystery set largely in restaurants in and near Washington D.C., is an odd conglomeration, a little like the culinary style known as Asian fusion. It’s full of intriguing ingredients, and there’s a lot to like about it, but it doesn’t quite add up.

Following the author’s acknowledgements, a section called "Cast of Characters" describes the protagonist and her lover, friends, relatives, colleagues, and enemies. While it’s never difficult to keep these 15 or so characters straight, authors trying to juggle dozens of characters could take a hint from this technique for tantalizing readers while keeping them on track. Here’s Sujata Massey’s description of Hugh Glendinning: "Rei’s live-in boyfriend who practices law and pillow-book maneuvers in the hope of getting Rei to the altar." How can you keep from reading on?

But then comes a prologue just over a page long and written in third person, in contrast to the rest of the novel, which is narrated by protagonist Rei Shimura. The events in the prologue take place after the events in the rest of the novel, and this creates some temporal confusion. Why the author didn’t make it an epilogue and write it in first person is only one of too many unsolved mysteries.

Early on we learn that the Japanese-American protagonist is no longer allowed to live in Japan, which, although it’s not her country of origin, is a country she loved. But the details are a little sketchy. "I’d been thrown out, for an indefinite length of time, by the government for a misdeed I’d committed in the name of something more important." Readers familiar with Sujata Massey’s other novels may be able to fill in the blanks, but the rest of us could benefit from a few more details. This also goes for Jiro Takeda’s origins. A fair portion of the narrative is devoted to creating suspicions about the former Iron Chef participant’s ethnicity, but the eventual explanation as the story is reaching its climax is so vague it’s pointless.

Still, this novel also has its share of saving grace. The characters could well be real people, and the author has a wonderful sense of place, whether she’s describing a restaurant bathroom or the Chesapeake Bay. The pacing is just right, and woven through a solid plot about the search for Rei’s friend Andrea’s mother, who disappeared thirty years earlier, is a lovely and unsettling meditation on motherhood itself. And Sujata Massey has a real gift for disconcerting brevity. I wish I had written Rei’s quip: "My grandmother and I had unfinished business that I intended to keep that way." When Rei’s cousin tries to make a point with a line she’s probably heard hundreds of times in her political circles — "Remember Watergate?" — Rei counters with "We were tiny babies then, Kendall. We can’t remember Watergate."

The Pearl Diver is particularly rich in contrast. Sometimes this is amusing: "Starbucks was strange," Rei muses. "In Kendall’s suburban neighborhood of Potomac, Starbucks was full of blond power moms like herself; but in my neighborhood, it was solely inhabited by Spanish-speaking men." But the contrast can also be profound: Rei notes that her Scottish boyfriend "didn’t even mind the Washington rain, because it reminded him of Edinburgh." But Rei herself, an odd sort of exile in her native country, "preferred the hard, blinding rain that made a rock-and-roll sonata on the tile roofs in Japan in the fall."

Sujata Massey received Agatha and Macavity awards for fiction, and she was an Edgar finalist. The Pearl Diver is her seventh book.