They knew getting Tom Brady to Ann Arbor might be a difficult sell. They knew, despite four Super Bowl rings and two MVPs, there were some sins he could forgive, but never forget.

In Ann Arbor, they still wince every time someone recounts the infamous story of autograph day, Brady's junior year. Michigan fans -- still glowing from winning a co-national championship the previous season, 1997 -- poured into the stadium and formed a line 50 yards long. They patiently waited to get a signature from the man everyone assumed would be the Wolverines' starter, following in Brian Griese's footsteps. But it wasn't Brady they were lining up for, it was freshman phenom Drew Henson, a Michigan high school legend. After a few minutes, someone ran to get Henson a table and a chair, and across the field, Brady stood by the tunnel for an hour, humiliated, signing his name only a handful of times.

If you're looking for the moment when the Brady legend found its motivational fuel, look no further. Brady won the starting job, but it never felt secure. For two years, coach Lloyd Carr made the upperclassman share time with Henson, and fans were constantly clamoring for Henson to unseat Brady. In 1998, Brady was booed off the field after making several mistakes in an early-season loss to Syracuse. Though he grew to understand how the adversity shaped him, the sting lingered.

Michigan coach Jim Harbaugh, right, was among those pushing for Tom Brady's return to Ann Arbor. Steven King/Icon Sportswire

Recognizing how Brady's mind works -- understanding how obsessively he catalogs his memories -- has always been essential to understanding him. If you want to know what he was doing in Michigan last weekend, attending a Wolverines game for the first time since he graduated, it's best to start with his brain.

Away from the football field, he has mastered the art of cool detachment, of projecting wry indifference. He can spend an entire news conference politely answering questions, looking you in the eye, nodding graciously, and then depart having said almost nothing of substance. His words, in public, feel as if they were made of smoke. There is nothing to hold on to.

"If you know Tom, you know he has a memory like a frickin' elephant." Jay Flannelly, who met Brady at Michigan and has remained a close friend for the last 20 years

His friends, however, know the other side of Brady, the zeal he has that's incessantly boiling just beneath the veneer. Slights, old and new, are woven into his DNA. He does not forget the times he has felt wronged, and he will ruminate on them for months, even years. This is typically a blessing. It has made him the player he is. He can, even now, name all six quarterbacks drafted before him in 2000, and from memory, he can tick off exactly where each was picked. He will hear a snide comment from an opposing defender, file it away for half a season, and pore over that player's tendencies in private, biding his time until he has a chance to enact a surgical revenge. His greatest asset, as a quarterback, has never been his physical skills. It's how ruthless he can be when he feels snubbed, or when his integrity is questioned.

Here, then, was the problem once Deflategate was mercifully put to bed: From the moment he reluctantly accepted his four-game suspension from the NFL, dropping his appeal just short of the Supreme Court, Brady's friends understood just how much he would obsesses over the games he was set to miss. He was remorseless, but powerless. His mind, and his obsessive nature, would now be a burden.

With Brady barred from the team facilities and unable to have contact with anyone on the Patriots, friends worried he might torment himself with so much idle time on his hands. When Wes Welker, a close friend and former teammate who is now retired, called to see if he'd like to grab dinner, Brady agreed on the condition Welker run routes and catch passes, too. His wife, Gisele, even posted a picture on Instagram of Brady throwing her passes in their backyard during the first week of his suspension. "Don't worry guys, I will have him ready," she wrote in the caption. Even in jest, the picture had a ring of truth to it. The man cannot stay still.

"If you know Tom, you know he has a memory like a frickin' elephant," said Jay Flannelly, who met Brady at Michigan and has remained a close friend for the past 20 years. "He remembers every little disrespect. I just wanted to get his mind off of everything for a few hours."

"We had to go kind of rogue to get it done." Todd Anson, a prominent Michigan booster who helped arrange the Brady visit

Phone calls were made, text messages exchanged, and eventually, an idea conceived: Perhaps this was the moment the University of Michigan could soothe some old wounds by inviting Brady to Ann Arbor to attend a game and serve as an honorary captain. Coach Jim Harbaugh -- who was convinced to return to Michigan in part because of an encouraging phone call from Brady -- was pushing for it. So were some of Brady's ex-teammates and current confidants.

The plan was for Michigan fans to shower their late-blooming prodigy with the love he'd never quite received when he wore the maize and blue. Perhaps, on some level, his suspension could be a blessing, an opportunity, a chance to bring him back into the Michigan family. He'd visited campus in February, for Michigan's Signing of the Stars, an event to introduce the Wolverines' incoming recruiting class, but according to someone briefed on the trip, it ended on an awkward note when someone from the school's fundraising department, unaware of Brady's complicated history with his alma mater, asked if he would be interested in donating a substantial sum to the school. Harbaugh, when he learned about the exchange, was livid.

The Michigan community wanted to do it right this time. It rounded up some of Brady's closest friends and former teammates, and reached out. Loyalty has always been important in Brady's life. How about the Colorado game in Week 3?

"We had to go kind of rogue to get it done," said Todd Anson, a prominent Michigan booster. "But it was important, because we knew Tom felt estranged from the program."

In a bit of a surprise, Brady accepted.

This is how Brady came to be standing on the 5-yard line of an empty Michigan Stadium on a Friday afternoon with a football in his hands. He'd brought his 9-year-old son, Jack, along for the trip, and was eager, according to a friend, for the two of them to spend a special weekend together since Jack lives primarily with his mom, actress Bridget Moynahan. One of the first places father and son went was the stadium, the Big House.

In the late-afternoon light, Brady gently lofted passes to his son, including one in the end zone that Jack caught as he was tumbling to the ground. Brady, giddy with pride, raised his hands in the air to signal a touchdown and jogged toward Jack. The boy scampered to his feet, paused, then dabbed like Cam Newton just before his smiling father embraced him, lifting him off the ground.

This, too, would be filed away, another Michigan memory. A new one.

Later that night, Brady's friends kept texting him, trying to get him to come out to the Pizza House, one of his old haunts. He politely declined. Eventually, he agreed to let them bring some food by his hotel. He spent his first evening back in Ann Arbor in 16 years nibbling on a chipati -- a salad stuffed inside some pita bread, a Pizza House special -- and playing board games with his son.

He returned to the stadium the next afternoon, game day, trying to look inconspicuous in dark sunglasses and a blue, half-zip Michigan pullover, but it was easy to spot the four-time Super Bowl winner. He lingered in the parking lot, waiting in a massive, cherry red Chevy Suburban for 20 minutes, before seeming to concede that the small swarm of media eager to document his arrival was not going away. He opened his door, offered a polite movie star wave to a large group of fans gathered on the steps of the stadium, and then walked briskly past the cameras and handshakes and autograph seekers without stopping. He said nothing, but flashed a cagey, aristocratic smile.

During pregame warm-ups, Brady milled through the crowd on the field, shaking hands like a politician, crouching down low to pose for pictures with groups of kids, laughing and pointing as he spotted old friends. Brady even posed for a selfie with Miami Dolphins owner Stephen Ross, a prominent Michigan alum and donor. Ross said he was texting the picture to Patriots owner Robert Kraft.

"Everyone who meets him gets that look that 16-year-old girls had the first time they saw the Beatles," Flannelly said. "But he's so disarming. He gets people to relax. He could talk to anybody. He could fix the Middle East. You put him in the room with the Arabs and the Jews and he would get them talking until they figure it out."

"I think I want to be a soccer player." Brady's son, Jack, asked if he'd rather be a quarterback or wide receiver

Jack Brady, dressed in a gray Under Armour shirt with a Superman logo, flitted about with a smile on his face, rarely taking his eyes off his father. At one point, according to someone who heard the exchange, one of Brady's friends asked Jack if he wanted to be a quarterback or a wide receiver when he grew up. Jack thought about it for a second, then delivered an answer that made everyone -- his father included -- laugh.

I think I want to be a soccer player, he said.

Harbaugh's plan was to have Brady address his team prior to kickoff, let him deliver a rousing pregame speech about what it meant to be a Michigan man. But first, the head coach wanted something for himself. He wanted to stand on the field where both of them had been once been Wolverines quarterbacks and, during pregame warm-ups, have a game of catch.

They started 10 yards apart -- two ornery, venerated Michigan quarterbacks from different generations -- grinning as they flipped the ball back and forth, a scene that looked like a lost page of Wolverines fan fiction.

Tom Brady plays catch with Michigan head coach Jim Harbaugh before the Wolverines' game against Colorado on Saturday. Lon Horwedel/Icon Sportswire

Brady's throwing motion, even in a casual setting, is textbook perfect, his right elbow tucked, his arms crossing one another with every follow through. Every Harbaugh throw, in contrast, looked creaky, his 52-year-old body twisting and straining to match the effortless zip of Brady's throws. But Harbaugh kept backing up, first to 15 yards, then 20 (then 25!), admitting later he was unable to resist making it a competition.

"When I look back on my career of playing catch with people, that was right up there with my dad," Harbaugh said later. "Tom has a good arm. He throws such a good ball. That ball almost catches itself. I wish I wouldn't have given him the wind."

Brady asked that no cameras be present in the room when he spoke to the team. He wanted to feel free to speak from the heart. According to those who heard his speech, Brady talked primarily about tradition, about what it meant to wear maize and blue. "It was a chilling speech," said defensive lineman Ryan Glasgow. "It made the hair on the back of your neck stand up."

"It made me realize maybe the greatest quarterback of all time was saying that I represent him." Michigan quarterback Wilton Speight

He went around the room and singled out each position, asking them to stand and look around the room and remember that they weren't playing just for themselves. They were playing for every great player who played their position or wore their number over the years. They were playing for Desmond Howard and Tyrone Wheatley and Braylon Edwards and Charles Woodson and, yes, even Tom Brady.

"It made me realize maybe the greatest quarterback of all time was saying that I represent him," said Michigan quarterback Wilton Speight. "That got me in the mindset that I wanted to go out and play even better than he ever did."

When he finished, the entire room erupted.

Just before the pregame coin flip, as Brady stood near the Wolverines sideline next to Michigan tight end Jake Butt, the school began showing a video of highlights from Brady's college career. He stood and watched, swaying in place, his hands clasped behind his back, gazing up at the 4,000-square-foot scoreboard, looking both appreciative and wistful. It was clear he was reliving old throws in his mind, retracing the lines of faded memories. He turned and waved to the crowd as fans roared with gratitude, then spun in a slow circle to acknowledge the whole stadium, soaking up love from some of the same people who once withheld it.

He kept his designer sunglasses on, a friend later speculated, as an emotional suit of armor. He didn't want anyone to know if his eyes welled up with tears.