Adapted by Clint Eastwood, who fared so well with slight material in his The Bridges of Madison County, and with a screenplay by John Lee Hancock, who wrote Eastwood's problematic A Perfect World, the film version achieves a little more coherence and focus, and its performances are for the most part savory and engrossing. Like the book, though, this Garden remains merely decorative, neither firmly rooted nor offering much in the way of bloom.

John Cusack is alternately endearing and annoying -- far too often he resorts to a reaction shot of dropped-jaw incredulity -- in the John Berendt (here John Kelso) role. He's a New York City journalist who visits the misty, mossy old city of Savannah to cover a party for Town & Country magazine (just one of many variations from the original text). It's the annual shindig held by Jim Williams, a nouveau riche antiques dealer and real-estate tycoon who's made his fortune renovating Savannah's decaying period townhouses. Played by Kevin Spacey in a silky moustache and with a bourbony, insinuating drawl, Williams exudes seductiveness and menace. In his first scene with Cusack, where he reveals that he'd specifically asked that Kelso cover the event, the predatory, homoerotic tension is palpable.

Not for long, though. Dramatic dynamics dissipate into quaint and coy cameos by the oddball locals. They include a man with live horseflies leashed to his clothing with threads, a fellow who walks an invisible dog, and the Lady Chablis (played by herself), a frighteningly gaunt and crude drag queen who looks like a cross between Eartha Kitt and Don Knotts. Such bonbons might be diverting in the laid-back, anecdotal format of the original text, but they're inert and inconsequential in a film. When violence strikes, with Williams shooting his hopped-up, brutish young handyman/lover, Billy Hanson (Jude Law), it hardly makes any more of an impression than all the other offbeat sketches.

Eastwood and Hancock wisely deviate from the book at this point, which has its narrator remain detached and colorless. Instead, Kelso becomes actively involved in Williams's attempt to prove the shooting was self-defense. Hoping to get a book out of the deal, and perhaps vaguely drawn to the enigmatic, sexually ambiguous Williams, Kelso works for the accused's good-ol'-boy lawyer, Sonny Seiler (Jack Thompson, sweet and smooth as a mint julep), and sets out on an investigation of his own.

What follows is a game attempt to harness Garden's odds and ends to a half-baked film noir. Kelso's trail leads him back to the increasingly irritating Lady Chablis, to a gratuitously inserted black cotillion ball, to various graveyard expeditions with a voodoo priestess named Minerva (Irma P. Hall), and finally to the city morgue -- this last in tow with Mandy (Clint's daughter Alison Eastwood, who doesn't embarrass herself but should lay off the singing), his perfunctorily tagged-on love interest.

After more than two and a half hours of this, he still doesn't get to the heart of the mystery -- because there isn't any. Although the film hints at issues like the elusive nature of truth and guilt, the corrupting effect of decadence and isolation, and the lures and pitfalls of sexual obsession, they're mere window dressing in its restored 18th-century colonial façade.