The future Mrs. Donald Trump was puzzled.

She had been summoned to a lunch meeting with her husband-to-be and his lawyer to review a prenuptial agreement. It required that, should the couple split, she return everything — cars, furs, rings — that Trump might give her during their marriage.

Sensing her sorrow, Trump apologized, Ivana Trump later testified in a divorce deposition, and said it was his lawyer’s idea.

“It is just one of those Roy Cohn numbers,” Trump told her.

The year was 1977, and Cohn’s reputation was well established. He had been Sen. Joseph McCarthy’s red-baiting consigliere. He had helped send the Rosenbergs to the electric chair for spying and elect Richard Nixon president.

Then New York’s most feared lawyer, Cohn had a client list that ran the gamut, from the disreputable to the quasi-reputable: Anthony “Fat Tony” Salerno, Claus von Bulow, George Steinbrenner.

But there was one client who occupied a special place in Roy Cohn’s famously cold heart: Donald Trump.

For Cohn, who died of AIDS in 1986, weeks after being disbarred for flagrant ethical violations, Trump was something of a final project. If Fred Trump got his son’s career started, bringing him into the family business of middle-class rentals in Brooklyn and Queens, Cohn ushered him across the river and into Manhattan, introducing him to the social and political elite while ferociously defending him against a growing list of enemies.

Decades later, Cohn’s influence on Trump is unmistakable. Trump’s wrecking ball of a presidential bid — the gleeful smearing of his opponents, the embracing of bluster as brand — has been a Roy Cohn number on a grand scale. Trump’s response to the Orlando massacre, with his ominous warnings of a terrorist attack that could wipe out the country and his conspiratorial suggestions of a Muslim fifth column in the United States, seemed to have been ripped straight out of the Cohn playbook.

“I hear Roy in the things he says quite clearly,” said Peter Fraser, who as Cohn’s lover for the last two years of his life spent a great deal of time with Trump. “That bravado, and if you say it aggressively and loudly enough, it’s the truth — that’s the way Roy used to operate to a degree, and Donald was certainly his apprentice.”

For 13 years, the lawyer who had infamously whispered in McCarthy’s ear whispered in Trump’s. In the process, Cohn helped deliver some of Trump’s signature construction deals, sued the NFL for conspiring against his client and countersued the federal government — for $100 million — for damaging the Trump name. One of Trump’s executives recalled that he kept an 8-by-10-inch photograph of Cohn in his office desk, pulling it out to intimidate recalcitrant contractors.

The two men spoke as often as five times a day, toasted each other at birthday parties and spent evenings together at Studio 54.

And Cohn turned repeatedly to Trump — one of a small clutch of people who knew he was gay — in his hours of need. When a former companion was dying of AIDS, he asked Trump to find him a place to stay. When he faced disbarment, he summoned Trump to testify to his character.

Trump says the two became so close that Cohn, who had no immediate family, sometimes refused to bill him, insisting he could not charge a friend.

“Roy was an era,” Trump said in an interview, reflecting on his years with Cohn. “They either loved him or couldn’t stand him, which was fine.”

Trump was asked if this reminded him of anyone. “Yeah,” he answered. “It does, come to think of it.”

Business, pleasure and power

The gossip columnist Cindy Adams, who knew everyone, had no idea who he was.

“This kid is going to own New York someday,” Cohn told her, gesturing at a tall twenty-something bachelor at a dinner party in the early 1970s. “This is Donald Trump.”

“Yeah, so?” Adams recalled replying.

Cohn, the son of a prominent New York judge, had taken an uncommon interest in Trump.

The two had met not long before at a private disco called Le Club, and instantly hit it off while discussing a nettlesome obstacle for Trump. The Civil Rights Division of the Justice Department was suing him and his father, accusing them of refusing to rent to black tenants. Trump told Cohn that their lawyers were urging them to settle.

“Tell them to go to hell and fight the thing in court,’” Trump later recalled Cohn advising him.

Trump did just that, with Cohn as his lawyer. Not only did Cohn countersue the government for $100 million, he filed a blistering affidavit on Trump’s behalf, mocking the case.

“The Civil Rights Division did not file a lawsuit,” Cohn wrote. “It slapped together a piece of paper for use as a press release.”

The Trumps ultimately settled the case by agreeing to make apartments available to minority renters, while admitting no wrongdoing.

For Trump, the benefits of his new representation were obvious. Cohn was one of the most famous and feared lawyers in America. He would later appear on the cover of Esquire beneath an ironic halo, and earn a posthumous parody on “The Simpsons.”

But Cohn saw something in Trump, too.

“He could sniff out a power-to-be, Roy could,” said Susan Bell, Cohn’s longtime secretary.

After helping convict the Rosenbergs as a young federal prosecutor and then working in Washington as a top aide to McCarthy, Cohn had returned to New York, starting a boutique practice in his shabby but elegant town house on East 68th Street.

The division of labor in the firm was clear.

“We called him the rainmaker,” said Michael Rosen, a partner who handled many of the firm’s organized-crime cases. “We did all of the grunt work, if grunt work means preparing the case and trying the case.”

Cohn lived on the third floor, often traipsing downstairs in his bathrobe well after the workday had begun and taking clients upstairs to a small sun porch. The elevator rarely worked. In the winter, the lawyers stuffed towels around the windows to keep out the cold.

Parties and business meetings tended to blur, with celebrities like Andy Warhol and Estee Lauder crowding in and spilling out. “That town house was a workhorse,” recalled Trump, a familiar presence there himself.

He and Cohn became social companions, lunching at “21” or spending evenings at Yankee Stadium in the owner’s box of Steinbrenner, another Cohn client.

After Fraser entered Cohn’s life, the two were frequent dinner guests at Donald and Ivana’s Trump Tower apartment, with its Michelangelo-style murals. They were also regulars at Trump’s owner’s box at the Meadowlands, the home of his sports team, the New Jersey Generals of the short-lived U.S. Football League.

Cohn was the master of ceremonies at a Trump birthday party at Studio 54; years later, Trump returned the favor with a birthday toast of his own at a party in the atrium of Trump Tower, joking that Cohn was more bark than bite.

“We just tell the opposition Roy Cohn is representing me, and they get scared,” Trump said, according to a cousin of Cohn’s, David L. Marcus, who attended. “He never actually does anything.”

Among the many things Trump learned from Cohn during these years was the importance of keeping one’s name in the newspapers. Long before Trump posed as his own spokesman, passing self-serving tidbits to gossip columnists, Cohn was known to call in stories about himself to reporters.

It was also through Cohn that Trump met the political operative who has played a leading, if behind-the-scenes, role in his campaign: Roger Stone.

When Stone, the roguish former Nixon adviser and master of the political dark arts, came to New York in 1979 to court support for Ronald Reagan’s presidential bid, he arrived with a box of index cards filled with the names of actors and producers. And Roy Cohn.

“I made an appointment and I pitched him on Reagan, and he said you have to meet Donald and Fred Trump,” Stone recalled in an interview.

Eventually, Cohn and Trump became so inseparable that those who could not track down Cohn knew whom to call.

Once, Cohn chartered a plane with friends, without Trump, trashing it during a midair party. He refused to pay. So the airline found Trump, asking if he could help.

He called Cohn, more amused than concerned.

“I said, ‘Roy, what are you going to do about this? I mean, you destroyed the plane,’” Trump recalled. “He said, ‘Eh, we’ll pay them someday.’”

Invaluable relationship

By the time Trump started getting serious with a Czech model named Ivana Winklmayr, Cohn had become something of an expert on marriage.

“It’s difficult to imagine and admit that the flush of the moment may become the flush of the toilet as the relationship goes down the tubes,” he wrote about the importance of prenuptial agreements in his book “How to Stand Up for Your Rights — and Win!”

According to “Trump: The Greatest Show On Earth,” a book by the journalist Wayne Barrett, Cohn advised Trump against marrying Winklmayr, but insisted that if he must, there had to be a prenuptial agreement. He would handle it himself.

The agreement, completed only weeks before the wedding, did not quantify Trump’s net worth — “impossible to accurately determine due to the illiquid nature of his holdings” — and took a bearish view of Trump’s earning potential and a modest view of his tastes.

“Donald’s standard of living is basically simple,” it said, calling Trump’s preferred lifestyle “neither opulent nor extravagant.”

When the marriage dissolved a few years after Cohn’s death, Ivana Trump’s lawyers charged that she had not had proper representation on the prenuptial. Her initial lawyer had worked for Cohn on at least one case, and was a frequent passenger on Cohn’s yacht, the Defiance. The divorce case eventually ended with a settlement.

The prenuptial was just one of many Trump deals, some more conventional than others, in which Cohn was intimately involved.

He used his connections to help Trump secure zoning variances and tax abatements critical to the construction of the Grand Hyatt Hotel and the Trump Plaza.

After one Cohn coup, Trump rewarded him with a pair of diamond-encrusted cuff links and buttons in a Bulgari box.

And if Cohn did not always feel comfortable charging a friend for his services, Trump was hardly one to put up a fight.

“Roy said, ‘I’ll leave it to Donald to give me what he thinks is fair,’” Fraser recalled of one lengthy Trump tax case in particular. “But, of course, Donald didn’t give him anything.”

Some work would have been difficult to bill. For instance, Cohn lobbied his friends in the Reagan White House to nominate Trump’s sister, Maryanne Trump Barry, to the federal bench. (Questioned last year about this, Trump said that his sister “got the appointment totally on her own merit.”)

“He was a very good lawyer if he wanted to be,” Trump said in the interview.

Asked about Cohn in 1980, Trump was more blunt in his assessment: “He’s been vicious to others in his protection of me.”

Defiant to the end

It started with a cut that would not stop bleeding.

Cohn’s diagnosis came not long after his former companion, Russell Eldridge, had gotten his. Eldridge had spent most of his final days in a private suite overlooking Central Park in Trump’s Barbizon Plaza Hotel.

Bell, Cohn’s secretary, recalled that Trump’s secretary, Norma Foerderer, had billed Cohn for the room, and later called to say that Cohn had not paid.

“I said, ‘Guess what, Norma, he’s not going to,’” Bell said. “And she kind of knew it.”

Cohn remained in his town house. Until the end — and even under interrogation by Mike Wallace on “60 Minutes” — he insisted that he had liver cancer, not AIDS.

He received experimental AZT treatments in Washington and continued working. But his clients could not help but notice that his health was deteriorating.

Trump started gradually moving cases elsewhere, he said, never telling Cohn why. “There’s no reason to hurt somebody’s feelings,” he said.

“He was so weak,” Trump added. “He was so weakened that he really couldn’t do it.”

Cohn never spoke about Trump’s decision, but was plainly crushed, according to Bell. She remembers it happening not gradually, but “overnight.”

Even as his health was failing, Cohn, whom government prosecutors had unsuccessfully pursued for decades on charges including conspiracy, bribery and fraud, faced a final indignity: He was facing disbarment. Among other offenses, he was charged with coercing a dying multimillionaire client — during a late-night visit to the man’s hospital room — to amend his will to make Cohn an executor of his estate.

The hearings were closed to the public. But true to form, Cohn, riding to the daily proceedings in a red Cadillac convertible, insisted on a spectacle, describing his accusers as “a bunch of yo-yos just out to smear me up.”

The prominent figures whom Cohn summoned to testify on his behalf included Barbara Walters and William F. Buckley Jr.

And, of course, Trump. He described his friend in simple terms.

“If I summed it up in one word,” Trump told the hearing panel, “I think the primary word I’d use is his loyalty.”

Gaunt, frail and besieged, Cohn nevertheless managed to attend a dinner with Fraser at Mar-a-Lago in Palm Beach, Fla., shortly after Trump purchased the property in late 1985. It was a last glimpse at his final, fair-haired project.

“I made Trump successful,” he would occasionally boast, according to Marcus, Cohn’s cousin, a former journalist who chronicled Cohn’s last months for Vanity Fair.

In June 1986, Cohn was disbarred for “unethical,” “unprofessional” and “particularly reprehensible” conduct.

To this day, Trump rues the outcome. “They only got him because he was so sick,” Trump said in the interview. “They wouldn’t have gotten him otherwise.”

During his final days, Cohn called Trump, ostensibly for no particular reason. “It was just a call: ‘How are things going?’” Trump recalled. “Roy was the kind of guy — I don’t think he ever thought he was dying, frankly.”

About a week later, in August 1986, Trump received another call.

Trump hung up the phone, repeating the news to an associate in his office: Roy Cohn was dead.

“I said, ‘Wow, that’s the end of a generation,’” Trump remembered. “‘That’s the end of an era.’”

Fraser inherited all of Cohn’s possessions: the town house, his weekend place in Greenwich, Conn., his Rolls-Royce, his private plane and much more. But the IRS, collecting on Cohn’s tax debts, confiscated nearly everything.

He did get to keep the cuff links Trump had given Cohn. Years later, Fraser had them appraised; they were knockoffs, he said.

Fraser soon returned to his native New Zealand, where he now works as a conservationist at the Auckland Zoo. He has not spoken with Trump since Cohn’s death, but he has no doubt that if his former lover were still alive, he would be an enthusiastic supporter of the Trump campaign.

“Having trained or mentored someone who became president,” he said, “that would have been quite exciting for Roy.”