Actress Melanie Mayron was describing a scene she played off-camera with Richard Chamberlain. On-camera she plays his secretary in "Wallenberg: A Hero's Story."

"I told him I thought it would be a good idea if a couple of times I might straighten his tie for him," she said. " 'You want to straighten my tie?' she remembered Chamberlain saying. She furrowed her brow like his and stroked her chin the way he did as he sauntered away to think about it.

Then he drifted back and asked her why she wanted to do it. To show a secretary's concern, she explained, to add a bit of mothering to the scene, to add a subtle action to the dialog.

"I asked him why he was troubled by the idea," she said. "He said, 'No one's ever invaded my hero-space before.'"

From well-received roles such as Dr. Frederick A. Cook in the TV movie "Cook and Peary: The Race to the Pole," to his portrayals of Lord Blackthorne in "Shogun" and Father Ralph de Bricassart in "The Thorn Birds" -- two blockbuster miniseries -- Richard Chamberlain has indeed quietly and persistently established himself as a player of heroes. Fiction or nonfiction, if there's a larger-than-life character to be played on television, chances are good that he will play it.

This week (Monday and Tuesday nights at 9 on NBC) Chamberlain takes the role of Raoul Wallenberg, a diplomat who left the comfort afforded him as a well-born, militarily- neutral Swede during World War II to win credit for saving more than 100,000 Hungarian Jews from being shipped off to Nazi concentration camps.

"The experience of getting this part was similar to 'Shogun' and 'Thorn Birds,' " said Chamberlain. "I'd been after it for three years. The ball landed in NBC's court, and I got to do it."

Chamberlain said that at one point Jon Voight was considered for the role of Wallenberg, a man who was a persistent thorn in the Nazis' side and who, at war's end, was arrested by the Russians. Questions remain as to why the Russians would jail someone who'd harassed the Nazis, and why the Swedes wouldn't work harder, sooner, for his release. A committee headed by Swedes is working now to secure his release -- assuming he's still alive.

"I find the man enormously intriguing," said Chamberlain. "I'm sorry to be 40 years too late telling people who he is -- or was. He would be 72 years old now, in a Soviet prison. The Soviets claimed he died in 1947. But as recently as 1978 he was reported sighted" in 1975.

Among members of the committee working on Wallenberg's behalf, the most often-heard theory on why he was arrested hinges on the idea that he received some money to support his effort from the United States, leading the Russians to think that he must be an American agent. Why else, the on Russian thinking goes, would anyone risk so much to help Jews?

"I came away from 'Wallenberg' feeling the unfathomable depth people can sink to and the extreme highs they can reach," said Chamberlain. "Wallenberg, through his perseverance, wit, magnanimity and his acting ability, was able to do incredible things. Why he did it -- I would have to talk with him about that.

"It's an intriguing question. Once I absorbed all the information I could about him, I treated his story as a fiction and filled in the gaps as best I could. I made up his feelings and inner life. I had to find the motivation."

Chamberlain indeed projects all those views of his character, who becomes convinced toward the end that he can single-handedly cow the Nazis. His prime antagonist is Adolf Eichmann, played in an understated -- and thus memorable -- fashion by Kenneth Colley. As the war winds down and Wallenberg and Eichmann discuss the Nazi's inevitable fate, Eichmann expresses no regret. He has enjoyed money, power and the finesores in Europe, he tells Wallenberg in the film. "I will go to the gallows with a smile."

Chamberlain's Wallenberg also encounters Baroness Kemeny, played by Alice Krige ("Chariots of Fire," "Ellis Island"). She aids Wallenberg and their friendship develops, within the limits of her marriage. Just like Father Ralph, diplomat Raoul doesn't get the girl.

The Wallenberg story is based on the book Lost Hero: The Mystery of Raoul Wallenberg by Frederick E. Werbell and Thurston B. Clarke. The script was written by Gerald Green ("Holocaust"), Dick Berg and Lamont Johnson. Johnson, who carries impressive credentials ("The Execution of Private Slovik," "Fear on Trial"), directed the filming in Zagreb, Yugoslavia. Berg ("A Rumor of War," "The Martian Chronicles") is the executive producer.

Chamberlain, who has an eye to becoming an executive producer himself, has been in Africa recently, working on a remake of "King Solomon's Mines," in which he reprises the role Stewart Granger played in the 1950 film. And there's another TV miniseries in the offing, with him playing John C. Fr,emont, politician, general and explorer of the American West.

One day, Chamberlain joked, he'd like to play a simpler character, with no hero-space to worry about. "I'd like to play the guy next door," he said. "With a couple of kids and a lot of problems."