In the end, Tom Brady just wanted to say goodbye -- in person -- to his longtime coach. But according to a new book to be published next month, Bill Belichick said he wasn't available and insisted the two New England Patriots legends talk on the phone.

Even though Belichick told Brady that he was "the best player the league had ever seen," Brady told a friend the fact it came over the phone was "telling" about how badly the duo's relationship had deteriorated over the years. The book, "It's Better to Be Feared," by ESPN senior writer Seth Wickersham, will be published Oct. 12 by Liveright Publishing. It's based on hundreds of interviews with a range of sources, including previously confidential emails, texts, game plans, scouting reports and internal New England studies -- including one in which Michael Jordan, Kobe Bryant, Tiger Woods and Brady were interviewed about personality traits that fueled their greatness.

The book reveals the inner workings of the secretive and controversial Patriots franchise that dominated the NFL from 2001 to 2019 and illuminates the power dynamics between the driven, proud trio of team owner Robert Kraft, Belichick and Brady. It also explores how some of the league's biggest names inside and outside of the organization dealt with the juggernaut. The success brought out the football genius and flaws of Brady, Belichick and Kraft -- and others throughout the league, Wickersham writes.

Wickersham writes that Brady ultimately left New England not only because both Belichick and Kraft refused to commit to him until his stated goal of playing until age 45 -- it was believed that Belichick thought Brady was close to the end -- but because he wanted to be at an organization that welcomed his input rather than ignored it, something he ultimately found in Tampa Bay.

"Tom Brady had been curious if there was another way of winning, and while nobody was arguing that Bruce Arians was a better coach than Bill Belichick, or even close, the seamlessness of Brady's proficiency and performance was making his former coach's methodologies look antiquated, even silly," the book says. "It was better to be feared -- but was it necessary?"

As examples of what the dynasty wrought, Wickersham writes that Kraft once called Belichick the "biggest f----ng a--hole in my life." Bill O'Brien told a colleague he tried to get fired as coach of the Houston Texans because he thought he might be able to succeed Belichick, the book says. Belichick and NFL commissioner Roger Goodell had a much closer relationship than previously known and once met secretly in a New England airplane hangar to discuss rule changes -- even as aides unsuccessfully pleaded with Goodell to drop the Deflategate inquiry, worried about the long-term damage to the league brand.

New England's historic run produced six Super Bowls in 19 years but also multiple controversies -- Spygate and Deflategate among them.

The book dives deeply into Kraft and his influence on the team and league, portraying him as an idealistic and patient leader and loyal friend to the league but also carrying a ruthlessness streak often most attributed to his head coach. In 2018, with the Pats' success and controversies wearing thin on all involved, Wickersham writes that Kraft, Brady and Belichick were trying to set aside grievances in order to remain victorious.

"Brady was tired of taking team-friendly deals with no input into how the money saved was spent -- and still wanted a long-term contractual commitment," Wickersham writes. "Belichick told associates that every organizational decision now was in support of Brady, geared toward pleasing him and making him successful -- and that Kraft meddled with the team, sometimes with opinions, sometimes with restrictive budgets.

"As for Kraft, in late September, he was in Aspen [Colorado] for a conference and bumped into a few friends in the hotel lobby early one morning. He told them he was leaving later for Detroit, where the Patriots were playing their next game. 'I hate leaving here,' Kraft said. 'You leave here and you leave some of the most brilliant people you've ever met. You pick up so much knowledge from all these brilliant minds. And I have to go to Detroit to be with the biggest f-----ng a--hole in my life -- my head coach.' "

"Bill was an idiot savant," Kraft told a confidant, according to the book, alluding to Belichick's reputation before he hired the former Cleveland Browns coach in 2000. "I gave him this opportunity."

The strain within the franchise had been coming for years, the book says. At one point years earlier, if there was an NFL franchise in Los Angeles, Brady might have tried to force a trade there, according to those close to him.

"Kraft sometimes groaned to confidants that Belichick didn't show him the respect he deserved, but he was in no rush for life after him," Wickersham writes. "Brady, though, seemed ready for it. ... 'I don't want to play for Bill anymore,' he told people close to him in 2017."

Ultimately, according to the book, Kraft, Brady and a few others discussed scenarios about who would replace Belichick. If offensive coordinator Josh McDaniels left after the season to be a head coach elsewhere, New England could hire O'Brien and he could perhaps one day succeed Belichick.

"The plan was fanciful," Wickersham writes, "but O'Brien heard about it. He was in a power struggle of his own in Houston, fighting with general manager Rick Smith, a 'dysfunctional' and 'toxic' situation, according to the Houston Chronicle. The leaks from O'Brien's camp, claiming he wanted out, were so aggressive as to be suspicious, as if he knew he had a golden parachute. In the end, though, the [Texans] chose O'Brien over Smith, giving the coach more control over football operations. O'Brien later joked to a confidant that it was a somewhat empty victory. 'I was trying to get fired,' he said."

Kraft, Brady, Belichick and the Patriots declined to be interviewed by Wickersham for the book, but they are quoted from on-the-record interviews with the author from the past two decades. The Patriots did not respond to requests for comment on this story.

Among other findings in "It's Better To Be Feared":

• At the 2008 league meetings, Belichick and then-New York Jets head coach Eric Mangini nearly had a fistfight. After a dinner for head coaches, Julie Mangini, wife of Eric, bumped into Belichick and said hi, trying to ease tension after the post-Spygate fallout. Belichick blew her off, and when she told Eric what had happened, he charged across the room and needed to be held back by other coaches from swinging at Belichick. "Hey Bill, f--- you!" Mangini yelled.

• After Spygate and during U.S. Sen. Arlen Specter's inquiry into whether the Patriots had videotaped the St. Louis Rams' walk-through practice before Super Bowl XXXVI, former Rams coach Mike Martz said he believed that New England had also videotaped the Rams practices during the week. "I'd like to hang Belichick by the nuts," he told a confidant.

• During Spygate, the Broncos' then-head coach Mike Shanahan backed Belichick and told Goodell that he wished he had videotaped signals and was disappointed for not thinking of the cheating methods himself. Goodell had called coaches and executives trying to learn more about New England's videotaping practices. Nearly all of them wanted Belichick severely punished -- except Shanahan. "You can't say that Bill Belichick is a bad guy," Shanahan told Goodell. "Bill is just better at it than most are."

• Brady's adjustment to worldwide fame early in his career was more difficult than he ever let on publicly. Cars would follow him home from work. At one point during the week leading up to the 2002 Super Bowl against the Rams, Brady literally ran from fame. He and some friends decided to hit Bourbon Street in New Orleans, and before they could even enter a bar or restaurant, a crowd formed around him so thick that all of them took off down the sidewalk and ducked into an alley, hiding until the fans had dissipated. "Our life has changed," Brady told his parents after the win over the Rams. "You're gonna change, and I'm gonna change."

• Toward the end of the dynastic run, Belichick commissioned an internal study to examine the traits of transcendent athletes. Jordan, Bryant, Woods and Brady were interviewed, among others. The study revealed that while the motivations of the rest of the elite athletes centered around the themes of rage and manufactured conflict, Brady was different. He felt most at the peak of his powers "not when he was measuring the size of the chip on his shoulder, but when he was in a loving and supportive environment," Wickersham writes.

• Team owners tried to negotiate the 2011 collective bargaining agreement with union chief DeMaurice Smith at Myra Kraft's funeral. Robert Kraft had tried to ease a contentious moment between the NFL and NFLPA then by attending CBA negotiations, even though his wife, Myra, was ill with cancer. After she died in July 2011, many team owners and Smith attended her funeral. It was during the lockout. Several owners tried to discuss the CBA and negotiate points at the funeral. "I wanted to throw up," Smith told a confidant.

• After Deflategate, Goodell was the public enemy of the Patriots. He decided to visit Gillette Stadium during a preseason game in 2017 against the Jacksonville Jaguars. He wanted to walk the field during warm-ups, take his medicine from the crowd and ease the tension so that he could return for the season opener, when the Patriots' fifth Super Bowl banner would be raised. The trip was doomed from the start. First, the league's plane broke down before it could take off. By the time the league secured another plane, Goodell was late and had missed warm-ups, ruining the point of the trip. League executives decided to leak news that Goodell was at the game to the Boston Globe. After reporter Ben Volin tweeted a grainy picture of Goodell in Kraft's suite, the owner hit the roof and yelled at league executives. "You're killing me with the fans," Kraft said. "Why would I want to be seen here with Roger with all this stuff going on with Brady?"

• Even though Goodell has heavily punished the Patriots three times for rules violations, he has become close with Belichick. Besides the secret meeting at a private airport to discuss rule changes, on the morning after the Patriots' Super Bowl win over the Falcons, Belichick hugged Goodell and lifted the commissioner's feet off the ground.

• In 2016, after then-presidential candidate Donald Trump read a letter of support from Belichick at a campaign rally, Patriots assistant coach Brian Flores told Belichick that several players were angry and that he "needed to say something" to the team. Belichick addressed the team, but it didn't help initially. Many players felt he was being disingenuous. "It was hypocritical and out of character," a Patriots player recalled. "I don't think he's an intolerant coach. He isn't a bad guy. Bill just f---ed up and justified it in a way that he would never accept from a player." After the meeting, a small group of Patriots players considered boycotting practice but then reconsidered.

• In the lead-up to Super Bowl LII against the Philadelphia Eagles, Patriots cornerback Malcolm Butler and defensive coordinator Matt Patricia traded heated words at practice over the former Super Bowl hero's lack of effort. Butler was demoted. At the team party after New England's loss, Butler responded to teammates asking why he was benched by saying, "These dudes," referring to the coaches, according to the book, "these mother f---ers."