It began with three simple words from defense attorney Arnold Weiner's secretary. "We've got it," she told Marvin Mandel over the telephone at 4:40 this afternoon.

Tears flowed on both ends of the line, and before the night was over, Mandel, his wife, Jeanne, his five codefendants and their many friends would celebrate the vindication they had said they were all confidently expecting.

From his secluded home in Anne Arundel County, Mandel told his many callers that he was too excited to decide whether to reclaim his office when he learned that an appeals court in Richmond had overturned his corruption conviction, spared him a four-year jail sentence and stripped the word "suspended" from his title of governor of Maryland, if only for the five days until Gov.-elect Harry R. Hughes is inaugurted.

"It's hard to explain the reaction," said Mandel, who had protested his innocence through two trials since his indictment, in November 1975. "I'm deeply grateful to all the people of Maryland who, during these trying times, have stood by myself and my family and I have been through unless you've been through it yourself. This is the vindication that's been a long fight to achieve."

Marvin Mandel was not alone in this fight, nor was he alone in the celebration. His vindication was shared by the five men who went on trial with him and by scores of politicians who had in many ways fallen from grace and power along with their leader.

At his Baltimore home, codefendant William Rodgers interrupted champagne toasts from family and friends by answering the constantly ringing telephone with the triumphant words: "Justice for all!"

Another co-defendant, William Rodgers' "this changes my whole outlook. Now I feel like I'm a full-fledged citizen again."

Harry Rodgers, who said he got the news while preparing to leave on a goose-hunting trip, said, "I was hoping for the best but looking for the worst. This restores my faith in the judicial system..."

At the State House, Acting Gov. Blair Lee III, the man who took over for his former boss 17 months ago and who, in the minds of his friends at least, may have lost his own bid for the governorship because of his loyalty to Mandel, rocked in his chair with unrestrained glee moments after he learned of the court's decision.

"I think it's wonderful, I really do," said Lee. "I firmly believe that just as people accepted the trial court's decision they shall accept this. I'm just delighted by it all. I'm happy for Marvin and for the state."

Lee's elation was blunted by some of his aides who drank Scotch with him and reflected on what might have been had Mandel been cleared before last September's primary election.

"Now we can get the new election," said one Lee assistant sarcastically. "All those people who voted against Blair because he suck with the man who has been declared not guilty. I wonder how they would vote now."

The acting governor was one of the first callers to reach Mandel when word of the court decision reached Annapolis. It was a brief and joyous conversation, Lee recalled. "Marvin was bubbling. I never heard him like that."

Lee said he called Mandel, at the request of the attorney general's office, to find out whether the man who served as governor for eight years planned to return to the State House and take over again for the final days of his second term. Mandel, according to Lee, Did not firmly answer the question.

"He said the letter he signed on June 4, 1977, (authorizing Lee to act as governor), was still in force as far as he was concerned," Lee said. "But he also told me he may call me later if he changes his mind."

Some of Mandel's former aides said they hope he will reassume power. Frank Harris, an executive assistant who was fired by Lee last year, said he and several other former Mandel aides will gather close to the State Hous Friday and wait for a signal from Nandel.

"Maybe," said Harris, "he'll want us to move back into our old offices."

The other question still unresolved at the end of the day's dizzying events was whether the U.S. attorney's office in Baltimore would seek to try Mandel for a third time, as the appeals court said it could.

U.S. Attorney Russell G. Baker Jr. declined to comment on the court's decision. The assistant U.S. attorney who prosecuted Mandel, Barnet Skolnik, has left that office to practice law with William Hundley, one of the defense attorneys in the corruption trial.

Mandel's first public appearance after the conviction was overturned came at 7:15 p.m. and lasted for about 10 seconds. He was nestled in the back seat of a car in the driveway of his secluded Anne Arundel County home, a pipe in his mouth, his wife Jeanne at his side.

Without opning the car window or saying a word to a flock of reporters and cameramen who had been waiting outside for two hours, Mandel sped off into the night, prompting a high speed chase down Ritchie Highway that ended with the press cars going one way -- toward the State House -- and Manel's car slipping off undetected in some other direction.

Shortly before midnight, Mandel and his wife went to the penthouse bar atop the Annapolis Hilton and recalled the day's events while drinking beer with a few close friends. Mandel said that when he got word of the reversal from Weiner's secretary he tried to call his wife, but she was in the shower, unable to answer the phone. He then drove back to their house, arriving just as his wife emerged from the shower.

"He said, 'it's been reversed,'" Jeanne Mandel recalled, "I said, 'you mean?' and he said, 'yes,'and we both wept."

Mandel was more visible in the hours before the decision. He spent the lunch hour at the Maryland Inn across the street from the State House, laughing and joking with the group of delegates from Baltimore. "It was almost as though he knew what was coming," said one of Mandel's luncheon companions. "He said he thought something good was going to happen."