LENOX, Mass. — At 5 p.m., the late-summer sun blisters, 91 in the shade. Christopher Lloyd, who created a repository of outsized characters, strides across the stage under a copse of soaring spruce. Swathed in three layers of eighth-century garb, he’s tackling that summit of Shakespearean roles, the mad monarch, King Lear.

At 82, Lloyd is the same age range as Lear, “fourscore and upward, not an hour more nor less.” The part is so punishing, even indoors without battling bugs and planes and epic humidity, that it is routinely performed by actors decades younger.

“I knew it was a beast, but something in my gut felt that I could meet the beast on my own terms. Out of nowhere, a lightbulb went off, and I thought, ‘Hey, what about giving it a shot?’ Certain directors, I’d say I want to do Lear, and they’re going to say, ‘Okay, Doc,’ ” Lloyd says the next morning, mentioning his most beloved role, as in it ain’t gonna happen. But Shakespeare & Company’s artistic director, Allyn Burrows, pounced at the suggestion: “Chris is well acquainted with the knife’s edge when you do one of these characters.”

Reviews have run the gamut. The Wall Street Journal rhapsodized: “a magnificent performer.” Local write-ups tended toward incendiary. The sold-out show runs through this weekend.

The long journey to Lear makes sense. Lloyd is, once again, portraying a man who has come undone.

Since his turn as the electroshocked Taber in “One Flew Over The Cuckoo’s Nest” — which garnered five Oscars, not bad for his first film — Lloyd has cornered the market on misfits and miscreants who exist outside the churn of society: Doc Brown (“Back to the Future”) Reverend Jim (“Taxi”), Uncle Fester (“The Addams Family”), Judge Doom (“Who Framed Roger Rabbit”).

Let other actors portray pretty boys and battle for star turns. Lloyd owns permanent, choice real estate in the pop-culture zeitgeist. The work became constant; the roles, indelible.

“Why would you want an actor as gifted as Chris, talented enough to play these weird characters and play them unbelievably, to do anything else?” asks frequent “Taxi” director James Burrows. “You can get a lot of actors to play just plain straight. Chris uses all his comedy tools.”

Michael J. Fox, Lloyd’s co-star and partner in what has become Back to the Future Inc., says, “It’s freeing when you retire from carrying the weight of leading man to being a character actor. It’s a lot more fun.” Working with Lloyd “is just different than working with anyone else. He is a genius at laying out exposition.”

Tall and lanky, Lloyd learned to dial down his natural good looks and leaned into the odd. Twitches became him. A facial contortionist, he deployed his mouth and eyebrows as comic weapons. He took easily to old. Lloyd was in his mid-40s when he first played Doc Brown, who appears to be the age of Methuselah.

“They’re kind of out there somewhere, not necessarily wacko,” he says of such characters, while sitting under a tent as theater campers declaim Shakespeare behind him in a sylvan field. “I like the challenges of making them real and believable in such a way that, no matter how far out or unlikable they may be, the audience sees something of themselves in that.”

Lloyd landed the laughs. He rarely landed a kiss. It took him until age 52 in “Back to the Future III,” he says, to score a romance (with Mary Steenburgen), that is if you don’t include his intergalactic affair as Captain Kruge in “Star Trek III: The Search for Spock.” They never meet in person. Then he blows her up.

His real life is another matter. Lloyd got the girl. And the girl. And the girl.

Five wives, one stepson with real estate agent Lisa Loiacono, his partner of 17 years. He refers to her as “my present, future, all-time wife.”

Offstage, Lloyd is taciturn, gracious. He is not only to the manner born, but also, though he rarely mentions his heritage, to the literal manor, a massive pile of bricks.

“He’s like putty. He can change so much. Chris was always the quietest of anyone,” says “Taxi” co-star Marilu Henner. “But he was always paying the most attention.”

He trained with Sanford Meisner at New York’s Neighborhood Playhouse, racked up 240 movie and television credits and played the circuit of the nation’s sterling theater companies: Yale Rep, Cambridge’s American Repertory Theater, Lincoln Center, the Public Theater. The longest he went without gainful employment? “The Sixties.”

Why does Lloyd continue acting at his age, especially in this heat?

“Do you have a pen ready?” asks Danny DeVito, who appeared with Lloyd in “Cuckoo’s Nest” and “Taxi,” the latter’s tightknit cast gathering for regular Zoom celebrations nearly four decades after the end of its glorious run. “He’s an A-C-T-O-R. He’s like a little boy when he’s working. I don’t think Chris ever had to act. He wants to get out there and play with the toys. He puts every single ounce of energy into a role.”

Lloyd’s career has been as wifty and out there as his characters. He collected a trio of Emmys and features in three National Film Registry treasures (“Cuckoo’s Nest,” “Back to the Future,” “Roger Rabbit”), yet accepts roles in cinematic piffle. He’s no snob. Kruge is among his favorite roles. But, he says, “I have to feel that I can do something with the part. I’m not that reckless.”

Starting off-off-off Broadway, “I was so thankful to have a job. I still am. When I get a call from my agent, my heart’s palpitating,” he says, his white hair and a beard grown long for Lear. “I can’t wait to open the script up and see what it’s all about.”

He’s voiced video games, including several for Back to the Future. Recent projects include a Hallmark Christmas movie (“Next Stop Christmas,” as a train conductor with “Back to the Future’s” Lea Thompson), animated fare, AARP romcoms and the A-list “The Tender Bar” directed by George Clooney and starring Ben Affleck, scheduled for release this year.

For the last, he wasn’t required to audition or test and shares significant billing as the “grandpa who mysteriously dresses in a suit Saturday night, drives into Manhattan and sometimes doesn’t come back until Sunday,” Lloyd says.

“George Clooney wants you,” Lloyd was told by his agent of 45 years.

“These are names that are out there that I’m aware of, but I’m not thinking that I’m going to work with them,” he says. “So it comes as a gift sort of out of nowhere.”

Lloyd was raised in New Canaan, Conn., on a Tudor estate named Waveny, today a municipal property available for wedding rentals. By third grade, young Chris was shipped to boarding school, his background similar to those of Doc Brown and Reverend Jim. Mayflower, or thereabouts. (Lewis H. Lapham, editor of Lapham’s Quarterly and former editor of Harper’s Magazine, is a cousin.)

“My grandfather and two of his associates were founders of an international company,” he says. “I’m not disclosing the name because I’m being that way, but this company’s logo is seen in the background in ‘Back to the Future.’ So there’s a clue.”

It’s Texaco.

There were expectations. His father went to Lawrenceville and Princeton, Yale Law. “He wanted me to follow in that vein, and I was a hopeless academic,” says Lloyd, the youngest of seven. “I just couldn’t get myself to do the work.”

But his mother was passionate about the arts, and an older brother acted, paving the way. (Lloyd’s late nephew, Sam Lloyd, appeared as lawyer Ted Buckland on “Scrubs.”)

“If I was in an awkward situation, to be able to amuse people kind of saved my skin,” he says. “I like making contact with an audience, making a character believable.”

Early in his career, he wondered whether he would remain an underpaid stage performer. Then, “Cuckoo’s Nest,” a buffet for actors. “It was a deep-water trip with Chris. He was in deep. Nobody really revealed themselves. We all thought we were that character,” DeVito says. Over time, “the movie filtered into our lives. We needed each other for the humanity they possess. Chris is just brimming with this gentle sweetness.”

Lloyd drove to California on the July Fourth weekend of 1976 in search of more jobs that paid. “In the theater, there was a kind of scorn, if I may say, for sitcoms. It was tantamount to selling your soul, so I came out with a little bit of an attitude,” he says. “I’m not proud of that.”

He auditioned for a one-time role on the first season of “Taxi,” a character in a permanent state of altered consciousness who officiates at the green-card wedding of Latka (Andy Kaufman) and a sex worker. For the audition, Lloyd appeared with stubble, in ancient jeans, jacket, sneakers (“belonged to one of my fathers-in-law”) and a chambray shirt, his hair a tornado.

“I’ve never seen a room laugh harder. It was a slam dunk,” James Burrows says. Lloyd was quickly signed to the second season. His audition attire became the character’s uniform. “We’d be idiots not to have him back. Don’t forget, to shine in a cast as good as ‘Taxi,’ you should be nervous going to play with that team. He pulled it off. He brings 99 percent to the dance.”

A signature Lloydian move is waiting an extra beat or three for the laugh while marinating in the musicality of his deep scratch of a voice. In the “Taxi” episode “The Road Not Taken,” he delivers a master class in timing, playing Jim when he was a straight, Glee Club-loving Harvard student who is resisting ingesting his first “funny brownie” opposite a manic, stoned roommate portrayed by a young Tom Hanks.

“He’s so committed to his rhythm,” Henner says. “He uses his body as an instrument, the physicality as total commitment.”

When “Back to the Future” came along, “Chris was reluctant to come in and meet. He wasn’t sure about the movie,” director Robert Zemeckis recalls. “I would ask him questions, and he would give one-word answers. He’s very shy.”

And yet, “We instantly knew. That’s the guy. That’s Doc Brown,” Zemeckis says. “He just had everything the character needed.”

As BTTF stans know well, the team initially did not have the right Marty McFly. They shot five weeks with another actor. Lloyd is too kind to name Eric Stoltz. The movie was not off to a propitious start.

“I wasn’t aware of the problem, being young and naive, so it was a shock to me,” Lloyd says. “I was really working to make the mark for those five weeks, to get that character straight. Suddenly, I have to do it all over again, and I’m thinking, ‘Will I do it again as well as I did it before?’ ”

Apparently, yes.

The movie blew up. It became 1985’s top domestic box-office draw, spawned two sequels and continues to attract new fans. The movies thrive off the partnership of Lloyd and Fox, who had perfected their timing from years on sitcoms. Lloyd’s Doc is youthful, his enthusiasm contagious. He’s an ideal companion — “my mentor, my Yoda,” as Fox puts it — and the antidote to Marty’s lethargic, risk-adverse parents. His explications always track, even when expounding on “the flux capacitor” and other time-travel hooey.

“It ain’t gonna die,” Lloyd says. “It has a great appeal. It answers the imagination, in terms of romance, family life. It just hits all the buttons.”

It still keeps him busy with ancillary videos and animated fare. “Back to the Future: The Musical” is playing London’s West End; Lloyd is scheduled to attend next month. He never tires of exclaiming “Great Scott!” or delivering the first installment’s coda, “Roads? Where we’re going, we don’t need roads.” He and Fox tour the frenzied circuit of fan-filled Cons, most recently at Awesome Con this month in Washington.

“It’s a bromance. We love each other,” Fox says. “Nothing in our lives will ever be on this level.”

Zemeckis also cast Lloyd in “Roger Rabbit,” where he never blinks, a nod to his character’s secret identity. After his stellar run in the 1980s and ’90s, Lloyd kept at it. Sometimes Bertolt Brecht off-Broadway, sometimes “Law and Order: Criminal Intent,” and sometimes “Donald Trump’s The Art of the Deal: The Movie” (as — who else? — Doc Brown).

“It used to be the horizon for death was way over the rim of the Earth. Now, it’s in my face,” he says. He dreams of playing Don Quixote onstage, to DeVito’s Sancho Panza. “And I can play Dulcinea,” Henner offers. The Sunshine Cab Company of La Mancha.

There is no itch to retire. “That’s not my intention until I can’t make my way to the set,” he says. “It’s necessary. It’s my mode of expression, just like a musician can’t stop himself from making some kind of sounds. So, yeah, why not make the best of it?”

Opportunities abound. Except one particular kind. “I wouldn’t turn down the leading man,” he says. Especially a romantic one, who isn’t unhinged or tilting at windmills.

“There’s still time,” he says. “That would be a challenge because I haven’t done it yet. I’d probably learn something.”

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