In August, Cronyn will go to East Africa for three weeks to finish a documentary composed of some extraordinary footage by cinematographer Simon Trevor, whom Cronyn and Tandy hired to accompany them on a safari in 1966.
"I've had a number of offers from people who said, 'We want to buy your stuff on lions' or 'We want to buy your stuff on wild dogs or flamingos,' because I had about 7,000 feet of film. But I didn't want to sell it piecemeal, and I couldn't get anybody else to do the whole thing, so I'm doing it."
Cronyn and Tandy bought the Easton house in 1984, the seventh in a succession of homes they owned, including one in Brentwood and another on a small island in the Caribbean.
Cronyn works in a marvelously sunny book-lined study in what had been an attic. Adjoining the office is a kind of sitting room, decorated with the two National Medals of Art presented to the couple by the President and Hillary Rodham Clinton last year.
"This is what Jessie used to refer to as the Sulking Room," Cronyn says. "The idea was that when one of us couldn't stand the other for one minute more, we could go in here and sulk. And I must say that I never remember it happening once, not ever, never."
Cronyn has had a second career as a writer. Having come to Hollywood initially to appear in Alfred Hitchcock's "Shadow of a Doubt" with Joseph Cotten and Teresa Wright in 1943, he later wrote treatments for the Hitchcock films "Rope" and "Under Capricorn."
More recently he has written four scripts with Susan Cooper. One, an adaptation of Anne Tyler's "Dinner at the Homesick Restaurant," was written 10 years ago but has just been bought by ABC for a TV movie. "Now we have to do what I hate to do, which is figure out cuts. I think it's the best thing we've done."
At Cooper's urging, he wrote a delightful autobiography, "A Terrible Liar," published in 1991. "She kept saying, 'Write it down, write it down,' because I get going on anecdotage. But, oh, it was hard work." The liar of the title, he says, is memory itself, not a characterization of the author. The memoir takes the Cronyns through 1966, with fascinating insights on the craft of acting.
It would seem an interesting idea to extend the memoir beyond 1966; there were adventures and triumphs yet to come.
"I think about it quite a lot," Cronyn says. Not least, of course, it would be a chronicle of a unique marriage. "That's what I would find most difficult. And I don't want to write, 'And then I played . . . and then I played . . . and then I played . . . ' or 'And then I slept with. . . .' " He laughs. "Just not my style."
As a speaker recently at the commencement exercises of the American Academy of Dramatic Arts in New York, Cronyn was asked what one maxim he would pass along to the graduates.
"I used that little poem of Christopher Logue's," he said, reciting it:
Come to the edge.
It's too high [said in a thin, timid voice]
Come to the edge [more emphatic now]
We might fall [a timid voice again].
COME TO THE EDGE! [roaring]
And he pushed them . . .
And they flew!
"I meant also to tell them about Orson [Welles]. I was lunching at Sardi's one day in the late '30s and Orson came over to say hello. I'd just seen his 'Julius Caesar.' He'd given it a modern dress, and it was the only time I'd really seen that work. It was a comment on fascism and very stirring.
"I said, 'Orson, what I admire about the production is your sheer courage.' He said, 'Courage?' Cronyn demonstrates how Welles took a giant step forward, as if off a cliff into space, and said again, 'Courage?' That's it , that's going to the edge, because you have to, to be good."
Cronyn and Tandy carried forward a tradition that is now a casualty of changing times: the theatrical tour.
"We played 'The Gin Game' about 800 times [starting in 1978]," he says. "We did 'The Fourposter' 600 times . We did Albee's 'A Delicate Balance' I think 400 times  and 'Noel Coward in Two Keys' 400 times . In the days when we were most active, we had the example of Helen Hayes and Alfred [Lunt] and Lynn [Fontanne]. I don't think I can make it sound significant or meaningful, but it was the thing one did, if you were lucky enough to have a success."
"The Gin Game" played very successfully even in the Soviet Union in 1979, with a simultaneous translation on earphones.
"It took some adjusting," Cronyn recalls, "because there was always a lag between the joke and the laugh, and you couldn't slow the whole play down to wait for what you knew was coming. But it produced one of the proudest notices we ever got. The director of the Moscow Art Theatre said, 'It takes a couple of actors from America to come and show us what Stanislavsky was writing about.' I was thrilled because as a young actor I devoured every word Stanislavsky wrote.