By Sam Toperoff

Other. 385 pp. Paperback, $15.95

More than a few times, Dashiell Hammett’s real life has become fodder for other people’s fictions — often, of course, with a mystery at the core. Joe Gores’s 1975 novel, “Hammett” (directed by Wim Wenders in 1982), features the young writer called to a missing-persons case by an old Pinkerton buddy. William F. Nolan’s novel “The Black Mask Murders” in 1994 launched a series with Hammett, Raymond Chandler and Erle Stanley Gardner investigating crimes in 1930s Hollywood. Bradley Denton’s 2011 short story “The Adakian Eagle” invented a macabre mystery around Hammett’s stint in the Aleutian Islands during World War II. And earlier this year, Owen Fitzstephen’s “Hammett Unwritten” finds the author at the end of his life, reflecting once more on the mystery of the black bird.

Intrigue stands out as the driving force in those appropriations of this iconic figure, but now comes “Lillian & Dash,” which takes an entirely different approach. Sam Toperoff’s novel traces the love affair between Hammett and playwright Lillian Hellman from their first meeting in Depression-era Hollywood through Hammett’s burial in Arlington National Cemetery in early 1961. Crime does play a small role — the murder of a union organizer — but only in a couple of chapters, a detour in the larger story of this conflict-ridden romance.

‘Lillian and Dash’ by Sam Toperoff (Other Press)

Toperoff’s book doesn’t claim to be a full or faithful biography of this relationship (check out Joan Mellen’s “Hellman and Hammett” for an exhaustive analysis). It’s a novel, striving to explore and illuminate something about the private and perhaps unknowable aspects of the couple’s lives together. Toperoff writes early on that “neither Dash nor Lilly was a great believer in love or marriage, which is why biographers are befuddled by their long, inconstantly constant relationship. None of those biographers understood the rare power of their love.”

Implicit there, of course, is that this book does.

“Lillian & Dash” captures both the tender moments of intimacy and the rough ones (“cruelty was in fact precisely what made the erotic obscene,” Toperoff has Hellman reflect), and he dramatizes nicely the roller coaster of exhilaration and exasperation as well as the complex interplay of infidelities on both sides. Equally compelling are the scenes in which these writers serve as creative muses for one another — or harshest critics, as with Hammett’s advice to Hellman about her work on the propaganda film “The Spanish Earth.” Toperoff charts Hellman’s uneven growth as an artist and political activist (successes like “The Children’s Hour” and “Toys in the Attic” bookending missteps such as “Days to Come”) as skillfully as he does Hammett’s stasis and decline (his screenplays for Thin Man sequels, the comic strip “Secret Agent X-9” and a series of radio plays rehashing old characters and plots). But the book also does a fine job portraying Hammett as a writer still striving. Toperoff has crafted a series of brief scenes that give a sense of Hammett in his later life and also explore his earliest, formative memories. Hellman’s letters from her time with Hemingway and Gellhorn in the Spanish Civil War and Hammett’s from his time in prison brim with emotion, and several cameos by Louis B. Mayer are tense, little dramas redolent of classic Hollywood power-brokering.

Although these individual scenes sparkle, the book’s overall pacing falters. Large swaths of exposition and introspection dominate, and alternating between Hammett’s and Hellman’s points of view often seems unnecessary. Even more distracting are the indiscriminate shifts from first person to third, and the various poses of the more distant narrator (Toperoff himself?), sprinkling the text with armchair psychoanalysis, literary criticism and a fair amount of editorializing.

There’s something exciting about a novelist filling in the blank spots that a traditional biography can’t quite touch, but Toperoff overplays his hand, sometimes undoing what’s been scrupulously recorded elsewhere. Having Hammett talk about the difference between decorative flag lapels and medals in his testimony before the House Un-American Activities Committee is politically persuasive, but transcripts clearly prove he never said it. And why locate Hellman in London when Hammett returns from prison, when in fact she was in New York prepping for his return? The search for “novelistic truth,” as he calls it, ought to have a little more regard for actual truth.

What emerges then is a book that illuminates not so much Lillian and Dash as the author’s interest in them: the two of them sometimes better than they were, sometimes worse, all of it treated with empathy if not outright affection, and then the rest of their lives stuffed in to make it look more like a story.

Taylor, a professor at George Mason University, reviews mysteries and thrillers frequently for The Post.