DES MOINES, Iowa -- The most powerful swing in all of minor league baseball begins each at-bat with a cold stare of indifference. And ends in a blur of violence. But when Javier Baez connects, when he syncs up his waist-high leg kick with the serpentine coil of his arms and his torso, what you marvel at is not the trajectory of the ball or the distance it travels. It's the sound that bat and ball make when they meet. It's a mixture of hunger and rage. A sledgehammer striking iron.

Even listening to him take indoor batting practice is mesmerizing. On a recent afternoon in August, Baez sings along in Spanish to "Esta Noche" by Justin Quiles as he waits patiently for his turn to hit, deep in the bowels of the Iowa Cubs' Principal Park. He fiddles with his fluorescent green batting gloves, cracks jokes with his teammates and bobs his head in time with the music, looking every bit like a baby-faced 22-year-old without a worry on earth. But when he steps inside the cage, his entire body, and his demeanor, hardens. A man emerges from the shadow of a boy, each swing unleashing an explosion of sound that reverberates off the facility's cinder block walls at a deafening volume.

"He has power like you've never seen," says Iowa Cubs manager Marty Pevey.

Two hours later, against the Nashville Sounds, Baez comes to the plate and annihilates a fastball, belting it off the right-field fence for an RBI triple, helping propel the Cubs to a 3-1 victory. It's a common occurrence. Through 63 games for the Triple-A Cubs this season, he's hit .315 with 13 home runs, 57 RBIs and a .925 OPS.

So why is Baez still in Iowa? It's the tireless storyline of the season, the routine question at pressers, the long, drawn-out plight of the second baseman perpetually stuck in the cornfields.

"He's doing really well," said Chicago Cubs manager Joe Maddon before Monday's game against the Indians, just a week before September's anticipated roster expansion. "The plan with him is just to continue to do well. Just because a guy starts doing well does not mean he has to be called up immediately."

Well, of course. But if only Baez's story were so simple. Coming into the 2014 season, ESPN senior baseball analyst Keith Law ranked Baez seventh on the list of baseball's top prospects, ahead of Kris Bryant and Jorge Soler. (Addison Russell was No. 3). That year, while Bryant and Russell remained in the minors, Baez dazzled in his big league debuts, blasting three home runs in his first three games in early August. That sizzling start quickly fizzled when pitchers learned he would chase pitches, even some a foot off the plate, and his strikeout total ballooned. Although he played solid defense at second, he whiffed 95 times in 213 at-bats and hit just .169 in 52 games.

"I really had a hard time learning how to swing the way they wanted because of how hard I swing," Baez says. "It's been really tough making an adjustment."

But he's been making one -- in Iowa.

Some 330 miles away in Chicago, the Cubs, who for years have been the subject of ridicule for their inept play, are boasting a wealth of young talent in their infield. Years of high draft picks, and a significant investment in player development, are paying off as fruitfully as anyone could have imagined. Bryant, 23, and Russell, 21, are two of the best young players in the National League. Starlin Castro has struggled this season, even being moved off shortstop for Russell, but he's already played in three All-Star Games for the Cubs and is just 25 years old. In one sense, Baez is a victim of circumstance. The Cubs -- who have the luxury of being patient for the first time in a decade -- haven't had room in the infield. Rumors even had Baez on the trading block as the team prepared for one final playoff push.

But Baez's minor league stay isn't purely circumstance.

Baez sits in the Iowa dugout during a game. Ackerman + Gruber for ESPN

DURING A GAME in late May against the Reno Braves, Baez approaches the batter's box. He looks anxious, his movements robotic. He stands well off the plate and takes a strike. Then he starts swinging, regardless of location. He exaggerates that leg kick, elongates his stride and lunges at the ball. He's come to the plate three times and been fooled badly each time. Every swing looks like he's trying to drive the ball over the golden dome of the Iowa state Capitol, visible beyond the center-field fence about 2 miles away.

His mind seems elsewhere, the pain still too raw.

Earlier that day, Baez spent close to an hour sharing stories about his sister, Noely, and his father, Angel, attempting to explain their impact on his life, and this season. It's hard to think of them in the past tense, he says, especially Noely. They were an important part of his journey, of the man he's trying to be. At the beginning of the season, after 21 "miraculous" years, Noely died from complications associated with spina bifida. She'd been his confidant, his inspiration and his biggest supporter. After the funeral, Baez was faced with questions we're all faced with at some point in our lives: How do you find time to grieve when the rest of the world doesn't stop and wait? Do you focus on family or your career? Do you make a selfish decision or a selfless one?

Baez chose family. He took a two-week leave of absence to be with his mother and brothers, and the organization didn't balk at granting it. While he was away, though, Bryant and Russell got promoted. Then, when it looked like his call-up time had finally arrived in June, he broke his finger sliding into second base.

"It's been really tough and frustrating," Baez says.

It's also been the most important season of his life.

SHORTLY AFTER NOELY was born, doctors in Bayamon, Puerto Rico, told the Baez family that she was unlikely to live more than a few hours. At best, she might make it through the night. Her spinal cord had not properly developed in utero, a condition they diagnosed as spina bifida. Her internal organs and circulatory system were a mess, and brain damage was probable. Javier was just 11 months old, far too young to remember what happened, but his oldest brother, Rolando (11 years old at the time), can still recall his parents' devastation. "I was just a kid, so it was hard to understand what was going on, but everyone made it clear she wasn't going to be around long," Rolando says.

Two hours went by, and Noely, a fighter right from birth, was still breathing. A day later, doctors revised their estimate. It's possible she could live a few weeks, maybe even months, they said. When those markers passed, no one was sure what to think. A year? A decade?

"As she started to grow up, that's when we started to realize: This girl isn't handicapped," Rolando says. "She's a miracle."

Javier was 7 when his mother, Nelida, sat him down and tried to explain to him and his middle brother, Gadiel, what spina bifida means, to help them understand why Noely couldn't walk, why she struggled to talk and why she needed to wear an electrical device with a wire connected to her brain to help circulate blood throughout her body. Medical complications often meant monthslong hospital stays for Noely, with Nelida refusing to leave her daughter's side. That put the boys in the care of their father, Angel, who became the family's No. 1 cook, coach and confidant, especially after Rolando was drafted by the Padres and left home to play in the minors. "My dad would do the craziest stuff to make us laugh," Javier says. "One day, my brother's baseball team won a championship, and Dad climbed up the net behind home plate to celebrate, all the way to the top, and then he didn't know how to get down. We had to call the police for help."

The boys found solace in baseball. Even at a young age, Javier's skill on the diamond was evident. Blessed with a wiry, athletic frame, strong hands and a salsa dancer's feet, and surrounded by baseball-loving brothers and cousins, Javier blossomed. His grandfather had been an excellent pitcher in the Puerto Rican League, but Javier was determined to go further. He patterned his approach at the plate after his favorite player, Manny Ramirez, and he went after baseballs as if they had wronged him and he was seeking revenge. "Inside the park, he was like a different person," Rolando says. "He carried himself like he'd been in the big leagues for 20 years. But then he'd come home, and he was just a little kid."

Javier wondered why God had given him a body capable of so much, yet had given his little sister a twisted spine and damaged lungs. The arrangement seemed mercilessly unfair, even to the boy blessed with the physical gifts. "I thought a lot about it," Javier says. "I thought, 'What if I could give her my legs? What if I could take her place so she could walk? But she didn't want that. She wanted to do things for herself."

Javier shared a special bond with his sister, Noely, shown here in 2013. Courtesy Javier Baez

ANGEL BAEZ WASN'T a large man, 5-foot-3, give or take an inch. But he was a hard worker who did his best to provide for the family. "We weren't rich or poor, but we had enough," Javier says. Angel cut grass for a living and was employed by Twins Landscaping, a large but local company, to care for the baseball fields and parks in Bayamon. He seemed tireless, indestructible at times, which was why his family was surprised one summer night when he came home from work and went straight to bed. Typically, he'd take his sons to play catch or hit grounders; but on this day, he was exhausted.

In the middle of the night, Angel stumbled to the bathroom and began vomiting. Javier, then 12, heard the commotion. Knowing his mother was sleeping at the hospital with Noely, he got out of bed to see if he could help. "I was holding him in the bathroom when he was throwing up," Javier says. "I told him, 'Hang on, I'll go wake up Rolando so he can take care of you.' As my brother was getting dressed, I came back to the bathroom and saw him lying on the ground. I tried to talk to him, to get him up, but I didn't have much power to do it."

It was then that Javier noticed the gash on his father's head. It seemed Angel had tried to stand, slipped and hit his head on the sink or the toilet. There was a deep gash in his scalp, and his hair was soaked with blood. The boys placed a frantic call to their mother, but by the time they got their father to the hospital, it was too late. Angel died, Javier says, as a result of that blow to the head.

"I just remember thinking 'No way this is happening,'" Javier says. "We went to my grandmother's house, and there were so many people outside, it was almost like a party. I saw my mom in the living room, and I told her 'I know Dad is not going to be here anymore, but we will be here for you. We have to be strong.' She calmed down some after that, but it was pretty bad."

He refused to let anyone see him cry. He was determined to be strong. But when no one was looking, he slipped into his grandmother's bedroom, shut the door and wept.

FOR A YEAR, the Baez family tried to scrape together a living in Puerto Rico, but it grew increasingly difficult. Nelida decided to move the family to North Carolina, hopeful they would, at least, have access to better medical care for Noely. Rolando, recently married, would stay in Puerto Rico.

The family had relatives in North Carolina who agreed to help with their transition -- "I honestly don't even know what part of the state it was," Javier says. "I just remember we moved to the middle of nowhere." -- but soon the family realized they'd made a mistake. Javier and Gadiel enrolled in a school with an English as a second language program but felt hopelessly lost. They were also horrified to find out baseball was only a seasonal sport in America.

"We had no friends; we didn't speak English; and it was 115 degrees outside, so we couldn't do anything," Javier says. "All I remember is hearing my mom cry every day."

Eventually, Javier delivered a childlike ultimatum: Either find us a better situation or let us move back to Puerto Rico. Nelida thought about it, called a friend she'd known for years (whose daughter also had spina bifida) and took another leap of faith. They'd give Jacksonville, Florida, a chance.

"At first, I thought it was boring," Javier says. "Back home, you hear noise everywhere. Puerto Rico is loud, and there is always something to do. Jacksonville wasn't like that."

Through 63 games this season, Baez hit 13 home runs. Here, he hits one out in June. Ackerman + Gruber

Baseball in Jacksonville, however, wasn't boring or foreign. It felt like home each time he put on a glove or stepped to the plate. He joined a travel team, made some friends and gradually learned English by chatting with his teammates (and watching television). He also added muscle to his lanky frame. "The first time I flew to Jacksonville was a year after they moved from North Carolina," Rolando says. "I went to a tournament in Lakeland to watch Javy. I couldn't believe what I was seeing. He looked like a grown man."

Midway through Javier's high school career at Arlington Country Day, the world of baseball scouts and general managers began to notice as well. He wasn't viewed as an elite prospect, not at first, but he kept destroying baseballs. It forced people to pay attention. His senior year, he hit an eye-popping .771 (64-for-83), with 22 home runs, 20 doubles and 6 triples. It was enough to persuade the Cubs to grab him with the No. 9 pick in the 2011 MLB draft and hand him a $2.6 million signing bonus.

As Baez's baseball stock was soaring, so too was Noely's situation. She was getting better medical care in the States, was attending a school she liked and was frequently on hand to watch her brother's baseball games. "She'd get really mad when I'd strike out," Javier says. "She'd yell at me, 'Get a hit! Get a hit!' So every time I'd hit a home run, I'd point right at her. She loved it."

Noely's brothers learned, over time, that it was unwise and unfair to put limitations on her. She didn't like to be pushed in her wheelchair; she insisted on doing it herself. If her brothers were going to horse around and throw each other into the family pool, she insisted on joining the fray, so they'd (carefully) toss her in the pool too. When they rode water scooters in the ocean, she begged to ride along, so they held her tight and bounced through the surf. When Rolando bought a motorcycle, he sat her on the back and took her for a ride. One of Baez's favorite memories of his sister will always be the day they took Noely to Disney World, a place she'd longed to visit for many years, and she zoomed down Splash Mountain. "My mom was so worried," Baez says. "But Noely was so happy. She screamed and screamed. She loved it so much."

THE DAY BAEZ made his major league debut in August 2014 against the Rockies, he strolled to the plate like a 10-year veteran. He felt ready. He'd been dreaming of this for most of his life. As a teenager, he had the Major League Baseball logo tattooed on the back of his neck, confident stardom was his destiny, and now here was his chance. Ten members of his family -- including Rolando, Noely and his mother -- were there in Denver to watch.

He struck out, then grounded out, then struck out again.

Baez's major league debut in 2014 started off strong. Here, he celebrates after hitting a home run against the Brewers. AP Photo/Stacy Thacker

When he came to the plate in the 12th with the game tied 5-5, he stared down pitcher Boone Logan, dug in his back foot, waggled his bat and hammered a fastball to the opposite field for a home run. As he rounded the bases, he pointed to the sky, then pointed to his family in the stands. Two days later, in the third game of his career, he hit two more home runs against the Rockies, becoming just the third player in baseball history to have three home runs through the first three games of his career. He was making it look easy.

But only at first. Over the next two months, he struck out at an obscene rate (41.5 percent of his at-bats). Five times, he earned a golden sombrero -- four strikeouts in one game. Nine other times, he had three strikeouts in one game. According to FanGraphs, 39 percent of his swings came on pitches outside the strike zone.

Privately, the Cubs were concerned his long and loopy swing wouldn't hold up over a full season. The Cubs had the luxury of tossing him in the lineup late in the year, the team far removed from the playoff chase. If he failed, there would be a larger discussion about adjustments he had to make and, likely, another stint in the minors. By season's end, it was clear something had to change. He signed up to play winter ball back home in Puerto Rico but had mixed results.

"He has to shorten his swing," says Iowa Cubs' manager Pevey. "Otherwise, he's going to continue to get schooled. When the barrel of the bat looks like John Daly's driver, it creates a huge loop. The bigger the swing, the sooner you have to start it. So you're tardy on the heater and out in front of the breaking ball. That's where his biggest issue is."

Baez insists he was listening in spring training this season, absorbing information, making changes. He was driving the ball to the opposite field during batting practice and in contention for the Opening Day job at second base. But with the Cubs looking like a contender for the first time since 2008, they no longer could afford to be giving away at-bats. Maddon called Baez one of the best young players he'd seen, but also cautioned that he was no lock to make the roster. "The entitlement program, it doesn't exist," Maddon said when asked about Baez in spring training. "Everything had to be earned."

In private, Baez was hurting. Years of medical procedures had taken a toll on Noely's body, and although her mind wanted to keep fighting, her organs wouldn't cooperate. She'd recently spent six months in the hospital because of problems with her lungs, and it looked as if she'd have to return.

"Every time the doctors would intubate her, her lungs would get weaker," Baez says. "It was really hard. She couldn't even get up. She couldn't talk. You had to touch her to let her know you were there because there were so many machines. I think eventually, she just decided she wanted to go instead of getting intubated again."

In the meantime, it looked for a brief time as if Baez could make the Cubs' Opening Day roster despite hitting poorly during the spring (.173 with 20 strikeouts in 52 at-bats). Multiple media outlets reported he'd been told he made the team. But in roster cuts, Baez was sent down to Iowa (as were Bryant and Russell). "He's so close to getting it figured out in the batter's box," general manager Theo Epstein told reporters. "We just feel like Triple-A is the right forum for him, the right venue to continue to make those adjustments and get locked in. He does everything else so well on the baseball field. He's not far from making it."

Even as he dealt with his disappointment, Baez couldn't stop worrying about Noely. He called his mother to get an update. She tried to assure him that things would be fine, that he should focus on baseball, but he was torn between two worlds.

Baez celebrates with teammates in Iowa. Ackerman + Gruber for ESPN

THE DAY BEFORE the Iowa Cubs opened their season, he showed up for practice. As he was getting ready to head to the field, he got a call from Gadiel, who was playing baseball at Tabor College: "I just talked to Rolando. He's with Noely. He was crying. You know he never cries. It's not looking good. I think it's time for us to go home. Right now."

Baez asked the Cubs to put him on the next plane to Jacksonville, and he cried the entire flight. He tried to prepare, to remind himself that Noely's entire life had been a miracle, that the 21 years she got were a blessing. When he got to the hospital, Noely was gone. He went into her room, held her hand and said a quiet goodbye. "It was really tough," he says. "Really bad."

At first he wasn't sure whether he needed time away from baseball to grieve. But the Cubs encouraged it. Some things, they told him, are more important than your job. So he went home. "I thought I had to be strong for my mom, and I had to keep her busy," Baez says. He put on his best stubborn, stoic face and assured everyone they would get through this together. They would be fine. For a month, the family talked, told stories about Noely and looked at pictures of her. Baez had her name tattooed on his forearm with an inscription in Spanish: Your hands never did any damage. Your feet never took a wrong step.

It wasn't until he returned to Iowa that he began to truly grieve. "I let everything come out of me when I'm alone," Baez says. "I still cry when I think about her, but I realize that's something normal. It's something you need to do -- show your feelings."

He channeled that sadness into baseball. In time he was wrecking minor league pitching again. He wanted to get back to the majors -- for himself, for his mother and especially for Noely. It was hard to stay patient. On bad nights, he'd swing at the ball with so much violence and torque that many of his at-bats would end with one knee in the dirt, the young slugger humbled by yet another whiff. He'd watch himself on video, try to keep his hands level, but it was frustrating. He'd always swung one way, dating all the way back to when his father and brother first taught him the game. Hard.

"He's working on trying to hit a ball 400 feet instead of hit it 700 feet," says Iowa Cubs hitting coach Brian Harper.

Finally, it looked as if he was going get his chance. The big league club had some interleague games coming, and there was an opportunity to add his bat to the lineup as a designated hitter. Two officials from the Chicago Cubs visited the team in Des Moines, and Baez knew they were watching him closely. "You kind of get that feeling when you know you're going up," he says.

One headfirst slide into second base on June 7 derailed all of that work. His finger got stuck on the bag as he slid past, and the pain was severe. He tried to stay in the game, insisting that he was fine and the swelling was nothing, but the training staff took one look at his hand (which was the size of a small balloon) and sent him for X-rays. A broken finger meant four to eight weeks of rehab. With the Cubs looking strong for the first time in forever, he was headed to Arizona.

"I'll be honest with you, rehab really sucks," Baez says. "Being in Arizona was really frustrating. I'm the type of person who likes to be moving around. I need to be playing every day. I couldn't do anything but sit and watch TV."

He didn't pay attention to the big league club while he was out. He didn't want to obsess over what might have been, but it was hard not to wallow. As soon as he was allowed to remove his cast, he started hitting baseballs off a tee with one hand. He slowed everything down to the basics -- good posture, short stride, hands cocked, solid contact. In time, you could hear the ball jump off his bat once again. When he got back to Iowa in July, Baez put together a seven-game streak of multihit games in which he hit .441.

"I know everything was frustrating, but it might have been the best thing that ever happened to him," Pevey says. "When he came back, his approach at the plate was shorter and quieter, and it looks like he's making veteran adjustments that could allow him to be really successful in the big leagues."

On Sept. 1, this coming Tuesday, teams can expand their rosters to 40 players, which is Baez's next possible opportunity to find his way back to the majors for the first time since Noely died. He thought, briefly, this was a lost season. Now he's likely to arrive when the Cubs need him most. He's even been running down balls in the outfield during batting practice in Iowa, in case the team wants to give him a chance to play right or left. It wasn't something anyone asked him to do. He just started one day, doing it on his own. You never know, Baez says, what opportunities life will bring.

"His time will be coming," Maddon said Monday. "He's definitely on the radar screen."

Baez still talks to Noely when he's alone, about his joys, his prayers, his frustrations and disappointments. He probably always will. "Every time she heard my name and knew I was going to go up and hit, she would go crazy," he says. "No matter how the game was going, how bad I was doing or how good I was doing, she was always there for me."

Eventually, he'll hit another big league home run, and he already knows what he'll do. He'll point to his mom in the stands as a thank-you for all she sacrificed. Then he'll point to the sky and think of his sister, imagining he can still hear the beautiful sound of her screaming with joy.