Call her superficial, but Susie B. Anthony Rabinowitz Gersten assumed her marriage was great -- and why not? Jonah Gersten, M.D., a Park Avenue plastic surgeon, clearly adored her. He was handsome, successful, and a doting dad to their four-year-old triplets Dashiell, Evan, and Mason. But when Jonah is found in the Upper East Side apartment of second-rate "escort" Dorinda Dillon, Susie is overwhelmed with questions left unanswered. It's bad enough to know your husband's been murdered, but even worse when you're universally pitied (and quietly mocked) because of the sleaze factor. None of it makes sense to Susie -- not a sexual liaison with someone like Dorinda, not the "better not to discuss it" response from Jonah's partners. With help from her toughtalking, high-style Grandma Ethel who flies in from Miami, she takes on her snooty in-laws, her husband's partners, the NYPD, and the DA (is the person arrested for the homicide the actual perp, or just an easy mark for a prosecutor who hates the word "unsolved"?), as she tries to prove that her wonderful life with Jonah was no lie. Susan Isaacs brilliantly turns the conventions of the mystery on end as Susie Gersten, suburban mom, floral designer, and fashion plate, searches not so much for answers to her husband's death as for answers to her own life. (Scribner, $25)