Almost from the day Wallace and Olga Thrasher settled near here in the placid mountain valley known as Little Creek, many of their neighbors found them mysterious.

The Thrashers were frequently flying back and forth to a second home in Florida. On the income of a charter pilot, they had built a stunning, 10-room home worth between $200,000 and $300,000. And they had a habit of paying even large bills in cash.

In recent months, puzzlement has turned to astonishment with the unfolding of a pattern of events befitting a James Bond thriller: a flaming plane crash on a fog-shrouded mountain, two baffling disappearances, a questionable Jamaican death certificate and a murder plot.

"If you look at the whole thing, you couldn't believe it," said Thomas Baird, commonwealth's attorney for Wythe County.

"The entire episode is very bizarre," said R. Keith Neely, a defense attorney. "It's the most amazing damn case."

Virginia and federal authorities say the drama has grown out of a major marijuana-smuggling operation that went awry in a series of betrayals, accidents and increasingly desperate acts.

The characters appear straight out of central casting:

* Wallace (Squirrel) Thrasher. A handsome, graying 44-year-old former clothes salesman, he is alleged to have led the drug ring and was briefly believed to have been the person whose body was found in the crash of a marijuana-laden plane on Virginia's Fancy Gap Mountain. His whereabouts are now unknown, and his wife says she is convinced he is dead.

Nicknamed "Squirrel" for his scampering running style as a high school football player, he prided himself on his physical attributes. He entered the Mr. Virginia contest and, on one occasion, according to his wife, wrestled a gorilla. "He was daring, and yes, he was adventurous," she said.

* Olga Thrasher. A striking dark-haired woman of 28, she is expected to appear in Wythe County Circuit Court here tomorrow on charges of plotting the murder-for-hire of a man said to have been a pilot for her husband's drug ring.

Prosecutors say the mother of two was acting on the belief that the pilot may have caused her husband's death and bilked them of $250,000 in drug money. Thrasher has denied the charges and says she was entrapped by officers.

Described as a talkative, impulsive woman, she was known for expensive tastes that ran from a five-carat diamond ring to a white Jaguar to a $10,000 dining room suite.

* Nelson King. The third person to emerge as a major figure in the six-month-long drama, the 38-year-old Maine native is being held in the Roanoke city jail on marijuana smuggling charges. Authorities allege that he was the pilot in the smuggling operation and the target of the murder scheme.

In the rural community here, Wallace Thrasher was known for his outgoing salesman's personality and his moneyed lifestyle at the couple's 12-acre, Jacuzzi-equipped residence in Bland County.

"I never met anyone who didn't like him," said George Litchard, regional manager of Piedmont's general aviation division at Roanoke, where Thrasher kept two planes. "The mechanics liked him. The girls in the office liked him. He was just a very nice guy."

For Olga Thrasher, who married him in 1977 after his release from a Mexico prison where he served two years on a drug charge, the life he provided was a dramatic step up.

Her poverty-stricken Portuguese mother had to give her up for adoption. When Olga met Thrasher, she was processing paperwork in a Florida airport.

Off and on since the mid-1970s, investigators tried to pin down marijuana as the source of the cash that Wallace Thrasher carried around in briefcases.

In 1978, authorities identified Thrasher as the owner of a vessel that ran aground near Charleston, S.C., carrying 18,000 pounds of marijuana, according to federal court records. Two years later, he was identified as the pilot of an aircraft carrying marijuana from Colombia to Georgia. He was not charged in either incident. In 1982, Thrasher was arrested in the Bahamas on a drug charge, but was not convicted, according to his wife.

Finally, on Oct. 17, a plane crash in Carroll County gave Virginia investigators something major. The Beechcraft Bonanza that went down in a thick fog on Fancy Gap Mountain was loaded with 570 pounds of marijuana valued at more than $500,000.

Litchard identified Thrasher to authorities as the man who paid the hangar and maintenance bills on the aircraft. "I don't think there's much question Thrasher owned it," said Litchard.

When investigators arrived on Thrasher's doorstep to question him, he was gone.

Olga Thrasher said in a telephone interview that the last time she talked to her husband was over the phone on the last Saturday in October, when he told her: "I promise I'll be home by Wednesday. I will fight . . . whatever to get home to you."

Thrasher said later, "When I didn't hear from him, he was dead . . . I knew in my heart." She held a funeral in Pulaski, Va., in November, and ran a paid death notice in a Roanoke newspaper.

The proof of his death, however, was not convincing to authorities. A Jamaican death certificate filed in a Florida court stated Thrasher died on Nov. 5 in a plane crash in Jamaica. Archibald Gunter, the island's director of civil aviation, who investigates airplane crashes, could find no record of the crash or the doctor who supposedly signed the certificate. "I presume that the death certificate is fake," he said.

Pressed by U.S. authorities for an explanation, Olga Thrasher has refused to talk, though a federal judge jailed her for a day in an attempt to force her to answer questions before a Roanoke grand jury. In February, a warrant was issued against her husband on charges of conspiracy to distribute marijuana.

There was something strange about the Fancy Gap Mountain plane crash, too. In the wreckage, officials had discovered a single body slumped beside bales of marijuana. Originally suspected to be Thrasher, the victim was later identified as 24-year-old Mark Moreland Bailey, an unemployed resident of Wiscasset, Maine.

Then, to their surprise, authorities learned that a second man had survived and slipped away before anyone arrived at the scene, despite injuries that one attorney involved in the case decribes as a broken leg and numerous lacerations.

That man, officials say, has been identified as Nelson King.

Carroll County Sheriff William H. Vass was one of the first to reach the flaming wreckage on the mountainside and he finds it hard to believe that a survivor got away. "I had two of my men there in a matter of a few minutes," he said. "I don't understand it."

The blood-covered survivor, authorities say, showed up in the yard of a nearby house and washed off his cuts with a garden hose. The woman who owns the house told the FBI that she gave the man a glass of water but refused to let him use her phone, according to one source.

Authorities said that King called Wallace Thrasher from a telephone booth in the parking lot of a nearby motel. Max Jenkins, an attorney for Olga Thrasher, said authorities believe King came to the Thrashers' Bland County home, where he was seen by the teen-aged son of a next- door neighbor.

Jenkins said authorities have told him that Thrasher then took King to a Florida hospital for treatment, presenting him as the victim of a motorcycle crash.

While authorities were puzzling over the problem of their vanishing suspects, the case took on still another twist. Prosecutors claim that Freddie Lee Gilbert, 31, who lived in the Thrashers' guest house alleged that Olga Thrasher was plotting King's murder. They say Gilbert agreed to cooperate by secretly taping conversations with her.

Melvin Stack, an assistant state attorney in Daytona Beach, Fla., where the murder allegedly was to take place, said Thrasher apparently believed King had failed to pay for a $250,000 load of marijuana and that her husband had been killed in retribution.

Wythe County Commonwealth's Attorney Baird said Olga Thrasher was looking for "revenge, more than anything."

According to a criminal complaint filed in a Florida state court, Thrasher gave Gilbert $500 and told him to buy a gun, "preferably one with a silencer." Gilbert was then to go to a motel room and "lean on" King while she questioned him about the $250,000, the complaint charges. Afterward, Gilbert was to "dispose" of King, "but to make it look like an accident," the complaint alleges.

Shortly before the meeting was to take place, authorities arrested King on charges of smuggling the marijuana found in the plane on Fancy Gap Mountain. He has pleaded not guilty.

Olga Thrasher, arrested on March 13 in Virginia, has been in the Wythe County jail since, awaiting trial.

She is charged with six counts of conspiracy and solicitation to abduct and murder King. She also faces a charge of murder for hire in Florida. In addition, federal authorities allege in court papers that the Thrashers spent $80,000 more between 1978 and 1982 than the income they reported to the IRS.

Their property and a farm in Bland County have been seized by the government.

Thrasher said in an interview that she only wanted to talk to King to answer "questions and doubts I had" about her husband's death, including the possibility that King had a role in it. She said Gilbert initiated the conversations about killing King. She said she wanted a gun because "you just don't go into those situations unprotected . . . . It was entrapment and it was harassment. They felt Wallace was still alive and somehow through me, to get to him."

She has said she still believes her husband is dead. "Anyone who knows Wallace as a family man, knows," she said. "My God, those two kids were his life."

Investigators say at this point they wouldn't be surprised either way.

The case has been so much like a movie that at least one person has thought about turning it into one.

Richard Brydges of Virginia Beach, one of Olga Thrasher's attorneys, said Richard Hamlett, a Roanoke developer and the husband of actress Debbie Reynolds, called him recently to discuss the possibility of a film.

As yet, it's a story without an ending. Said Neely, Thrasher's attorney, "This is just kind of the surface."