Sometimes fact is stranger than fiction. Nonfiction writers have taken that old addage to heart, releasing books based on true stories that seem more improbable than anything made up. The two most notable examples, Midnight in the Garden of Good and Evil and The Hot Zone, might be steeped in fact but have plots more interesting than any fiction books in recent memory.

A killing took place in Savannah, Ga. on May 2, 1981. The accused was Jim Williams, a wealthy antiques dealer. The victim was Danny Hansford, a volatile gigolo who may have been Williams' lover. Was it self-defense or a willful act of murder?

Those questions make up the plot of Midnight in the Garden of Good and Evil (Random House), John Berendt's fascinating first book. But the book's heart belongs to Savannah.

Berendt, former editor of New York magazine and a regular Esquire contributor, stuffs the book with a cast of eccentrics, from Luther, a man trying to breed glow-in-the-dark goldfish, to Chablis, an outspoken transvestite. Those characters and several others make up the odd population of Savannah and provide countless subplots to the story.

The circumstances surrounding Hansford's death soon take back seat to the city itself. Savannah, after all, is the book's main character, a fact that Berendt is well aware of.

In honey-smooth prose he describes the city as a decadent oasis, a real-life Shangri-La where the champagne always flows and voodoo priestesses roam the moss-shrouded cemeteries.

Hansford's murder and Williams' subsequent trial are not neglected, though. Berendt gives us every bizarre detail and leads us to its appropriately odd resolution.

Reading Midnight in the Garden of Good and Evil is very much like traveling to a small Southern town. It is slowly paced and takes a long time to get there. But once you have arrived you realize it was well worth the wait.

On the other hand, Richard Preston's The Hot Zone (Random House) wastes no time in telling the story of a deadly virus strain that infiltrated the United States in 1989. At a breathless pace, Preston sets up the characters --real life scientists working for the government, their situations and thrusts us into the creepy, terrifying world of lethal diseases.

Before introducing the characters, though, Preston makes sure he introduces the disease first. The book's opening chapter describes in gory detail the effects of the disease on one man. It is one of the most suspenseful, horrifying passages ever written. Seriously.

The book's plot is oddly similar to Michael Crichton's classic thriller, The Andromeda Strain. Only this virus is real and the events actually happened.

The Hot Zone is science nonfiction at its best. Preston wisely keeps the biological explanations to a minimum, focusing instead on character development and the true terror of the disease itself. Very rarely does scientific babble get in the way.

Unfortunately, the book slows down greatly at the end. In fact, the unnecessary final chapter brings the whole thing to a screeching halt. But that is just a mild complaint. The rest of the book is relentless.

Other related nonfiction books that are worth a look:

--In Cold Blood by Truman Capote -- The first true crime novel about a family's murder in a small town.

--Shot in the Heart by Mikal Gilmore -- A memoir by the brother of Gary Gilmore, a mass murderer executed in 1977.

--The Coming Plague: Newly Emerging Diseases in a World Out of Balance by Laurie Garret -- A expansive look at dangerous, recently discovered viruses.