Stranger Than Fiction : Mystery: The case of Ambrose Bierce, the disappearing author, may have been solved by the publisher of a new collection of the writer’s short stories.

Ambrose Bierce was a bitter old man in 1913. He drank like a fish and spewed invective like a volcano. Hot-tempered, sarcastic and vain, he had alienated his friends and failed as a writer. At 71, he seemed justly destined for oblivion.

Then he made a great career move.

Saddling up his horse in El Paso, Tex., he crossed the Rio Grande, riding into the maw of the Mexican Revolution.

Sometime after Christmas, near Chihuahua City--where warlord Pancho Villa was operating--the former San Francisco newspaperman vanished.

Intentional or not, Bierce’s disappearance proved to be a masterstroke, more enigmatic than a UFO abduction, murkier than a Beirut kidnaping. It imparted mystique to the man and helped spark interest in his dark, angry fiction--a handful of bleak, brooding, bloody Civil War stories and short horror fantasies oozing a preoccupation with death.

Bierce’s fate became an enduring mystery and literary legend--the American writer devoured by a historical black hole.

Almost certainly, Bierce, best known for his vitriolic “The Devil’s Dictionary,” perished in a current of revolutionary violence. But there was no evidence.

Theories abounded. He had been shot by Villa. He had returned to the United States and lived in anonymity--or died in an insane asylum. He was killed in the siege of a Mexican town in January, 1914. He took his own life, fulfilling his endorsement of suicide as a noble act.

The riddle of his fate has stumped all comers: Secret Service agents, Pinkerton detectives, newspaper reporters, scholars and amateur sleuths. Most recently, novelist Carlos Fuentes speculated on the end of Bierce in “The Old Gringo,” adapted into a much-panned 1989 movie starring Gregory Peck and Jane Fonda.

Nearly 80 years after Bierce cantered into limbo, James Robertson walked into San Francisco’s Albatross Book Shop, where he stumbled onto a potential solution to the Bierce puzzle.

A publisher of expensive limited-edition books, Robertson was planning a lavish volume of Bierce’s Civil War fiction, “One of the Missing: Tales of the War Between the States.”

(The book, illustrated by San Francisco artist David Page, was published last month and contains such stories as “An Occurrence at Owl Creek Bridge” and “Chickamauga.” Like the press’s other handmade offerings, it is not cheap. But even so, the luxurious volume has attracted a few buyers. Oversized and printed on heavy cotton paper with a hand-sewn binding, the 30 copies printed are priced at $1,725 each. A cheaper 75-copy edition is priced at $975.)

At any rate, while in the bookshop Robertson discovered a biography of the short-story writer and newspaper columnist written by a former drinking buddy, an obscure San Francisco dentist named Adolph Danziger DeCastro.

As he does with every project undertaken by Yolla Bolly Press of Covelo, four hours north of San Francisco, Robertson learned all he could about Bierce and his work. It wasn’t always easy. Robertson found DeCastro’s 1928 effort almost unreadable. In fact, the self-serving book is so bad that one Bierce expert reportedly couldn’t finish it.

But Robertson persisted. And at the end, he found what he believes is gold: DeCastro’s account of his interview with Pancho Villa some years after Bierce’s disappearance.

Traveling to Mexico, DeCastro went to Villa’s hacienda, where he had dinner with the Mexican revolutionary. Nervous in the presence of so many armed, glowering men, DeCastro gently and obliquely raised the topic of Bierce. Wisely, DeCastro pretended to be an enemy of Bierce, who had allegedly taken a woman from the dentist.

“It would have given me pleasure to put a bullet in the heart of an American who was serving with your forces, my general,” DeCastro recalled telling Villa. “It is probably too late, for that devil was old in sin, and no woman was safe with him.”

When Villa learned the name of the scoundrel, DeCastro reports that Villa responded: “I knew him. He will not bother you and your woman any more. He has passed.”

Villa also told DeCastro that Bierce had not changed his drunken, loudmouth ways and had criticized nearly all the officers in his army. “I treated his vaporings with contempt,” Villa said. “An American who drinks too much tequila soon loses himself.”

After the dinner broke up, Villa’s brother Hipolito provided another outburst against Bierce: “This old cabron (bastard) sat for days drinking tequila, and in his drunkenness criticized my brother--imagine this!”

Satisfied that he had learned as much as he safely could and anxious to get away, DeCastro took his leave, saving the tale for his Bierce biography.

From what he has learned of Bierce’s psychology, Robertson believes DeCastro’s account “is not only plausible but has an odor of authenticity about it.” He has been promoting this opinion in lectures about Bierce, including a recent talk to the Book Club of California in San Francisco.

In his heyday, Bierce was well known in the Bay Area for his temper and for his reputation as a crack shot with a .44-caliber pistol, Robertson says: “He was very easily offended. Apparently, he had one of the world’s shorter fuses.”

Thus, he might have insulted a revolutionary general, might even have enjoyed it despite the consequences. Moreover, he was accustomed to violence, having served with distinction as a Union volunteer in the Civil War. He fought at Shiloh, was promoted from the ranks to lieutenant and was wounded three times.

Bierce also had a lifelong preoccupation with death and suicide. At 16, he had a dream in which God and mankind had died, and he saw his own decomposing corpse--a scene later included in one of his short stories. As an adult, he frequently spoke in support of suicide. His stories often hinged on bizarre death, and he was fascinated with patricide and matricide. One of his tales begins: “Early one June morning in 1872 I murdered my father--an act which made a deep impression on me at the time.”

Shortly before he left this country, Bierce visited the battlefields where he had fought--a farewell tour by a man who might have been seeking his own death. Robertson notes too that Bierce had endured the death of two sons and a host of professional disappointments. At one time, Bierce claimed he had made less than $100 from his now acclaimed fiction.

But Robertson also concedes that DeCastro was a suspicious character. Based on the biography of Bierce, DeCastro wanted to inflate his reputation as much as Bierce’s, Robertson says. Trying to find out more about the dentist from other sources, Robertson was able to find only one detail: DeCastro was arrested once in Los Angeles for impersonating a physician.

On the other hand, historian Page Smith, author of “The People’s History of the United States,” writes in the introduction to “One of the Missing” that DeCastro’s rendition of Bierce’s fate has “a certain plausibility.” But Smith steers away from endorsing the story.

“In any event, he sealed his earthly fame by the manner in which he departed the planet,” Smith writes. “He became more famous in death than he had been in life and cast about his name a splendid cloak of mystery that will ever allure.”

But perhaps Bierce should have the last word.

In one of his final letters, he wrote: “Good-bye. If you hear of my being stood up against a Mexican stone wall and shot to rags, please know that I think it is a pretty good way to depart this life. It beats old age, disease, or falling down the cellar stairs. To be a Gringo in Mexico--ah, that is euthanasia!”