BOOK REVIEW : There’s No Easy Story to Tell When the Character’s Complex : MAN KILLS WOMAN <i> by D.L. Flusfeder</i> ; Farrar Straus Giroux; $20, 370 pages

Just imagine, D.L. Flusfeder says in his first novel. Imagine you’re an unemployed sportswriter and sometime poet, a die-hard Red Sox fan, ducking your imminent marriage as if it were a fastball high and inside. Over a picnic lunch on the Boston Common, an English publisher (young, female and lovely) offers you an assignment--actually, another life:

Go to London and write a biography of one William Ivory (1925-1980), war hero, author, gambler, seducer, gourmet chef, psychotherapist and, the publisher insists, a “monster.”

If you’re Richard Tierney, you go. And you discover that your task isn’t simple.

For one thing, you’re an innocent abroad in a shifty, ingrown, secretive country that seems to have experienced its last vital moment during the Blitz in 1941. For another, the expected advance from the publisher fails to arrive, and you have to sneak out of your hotel with the bill unpaid. For another, the first few people you interview about Ivory range from uncooperative to downright strange:

A thalidomide victim with flippers for arms who challenges you to fight. A mummified old woman with Parkinson’s disease--Ivory’s adoring, if often-betrayed, first wife. A pub pianist who talks in rhyming riddles--a former patient of Ivory’s, obviously uncured. A professor who wrote Ivory’s obituary and plays a violent game of croquet. An aging, alcoholic bohemian who tells wonderfully atmospheric stories about Ivory that may be untrue.

Anybody but a Red Sox fan, inured to disappointment, would give up, but Tierney hangs in there. With him, you get drunk and stoned, teased and insulted; you visit punk dives and stately homes; you wade through letters, diaries and eyewitness accounts; you get thrown off tour buses and hustled out of aristocratic front doors--and, all the while, questions multiply:

What’s going on with the publisher, who appears and disappears and seems to be playing Tierney for a fool? Will he ever “get” her, romantically speaking? Was Ivory a murderer, as some sources allege? How did he die? What became of his Japanese second wife? Did he really leave behind a final, tell-all manuscript, a bomb ticking under the reputations of his upper-class cronies?

Above all, how should Ivory be judged? He was responsible for several deaths. He lied. He was a bigamist. He warped his children’s lives. He tried to jolt his patients out of their neuroses with “therapy” that included Russian roulette. He preyed on middle-aged virgins and described his conquests in letters to his first wife. His magnum opus was titled “Decadent Pleasures.”

But there’s another side to Ivory. He was a victim of class prejudice. Like his hero, Japanese author Yukio Mishima, he turned his life into a kind of art. He had courage and style; he made most of the people around him look hollow.

As Ivory’s daughter tells Tierney: “He understood what went on inside people and he hated it so he would damage it. . . . He did things to people, dangerous mean things, because he understood. “

An ex-lover says: “He was evil and he was not. He was the most agreeable interloper into some otherwise ordinary lives.”

Though this is primarily a novel of character, Flusfeder writes it as a thriller. Tierney “tells” the story to the publisher, in tones of bafflement and rage that don’t fit his careful withholding of key facts in the interests of suspense. The plot, detached from the rest of the novel, doesn’t add up--too many secrets that shouldn’t be secrets--and, in the end, neither Tierney nor the publisher quite coheres as a human being.

Still, taken as a whole, “Man Kills Woman” works, sometimes brilliantly. This is a story about decadence, and decadence is all about glittering surfaces and shaky underpinnings, the iridescent shine on rotten meat.

Flusfeder has so much fun in this book--his minor characters are so juicy, his descriptions so ripe, his send-ups of English voices so wickedly overdone, his narrative embellished by so many splendidly unnecessary touches, from a Whitmanesque catalogue of ballplayers’ names to a lethal parody of a Midsummer’s Eve party--that we can’t help but have fun too.