Warning: This story contains a graphic image.

Consider her grip. It is the most unseen element of her skill set, yet the essence of her game flows from its control and precision. The shifting configuration of her palm and fingers on the rounded octagonal handle determines the angle of the racket face, which in turn dictates the pace, spin and trajectory of a shot. The fan's eye naturally tracks elsewhere: the ball, her feet, her outstretched arm, her expression. But Petra Kvitova's dominant hand, armored with calluses and trained like a trellised vine around the same shape since childhood, is at the root of her strength.

And now imagine that grip closing over the cutting edge of a knife with all the adrenaline of self-defense and the force of a two-time Wimbledon champion and yanking it away from her throat, where an intruder had held it. The blade bit deeply into the fingers of Kvitova's left hand.

She flexes the hand in late April, almost a year-and-a-half later, to demonstrate that she can't clench her fist in celebration quite as tightly as before. Her long fingers curl into her palm, leaving a small space at the center, as if she's cupping something fragile. The scars are thin and faint, but residual clumsiness still causes her to fumble with objects sometimes.

"I'm happy that I have all my fingers, at the end of the day,'' Kvitova says.

She's feeling light and grateful on the day before her opening match at the WTA tournament in Prague, an event she watched from the stands last year, not yet ready to test her hand in a match. A jazz recording croons softly in the lounge of the downtown InterContinental Hotel, where Kvitova has permitted herself a slice of chocolate cake and a cappuccino with soy milk.

"Being in the top 10, it's a little bit weird for me," says Kvitova, 28. "In a year? I couldn't really expect that. But when the last season finished, I was already feeling more normal. To have the same start of the season as the other girls, same offseason preparation, everything. So, I feel normal."

At the behest of investigators, Kvitova has never divulged the details of what happened in her apartment on Dec. 20, 2016. She would rather not return to that moment anyway. It's what she did with it that matters and explains how she has created an extraordinary new normal.

Kvitova wins her opening match in Prague the next morning before a full house as fans who were turned away peer through a hedge and a windscreen in hopes of catching a glimpse of her on the tidy center court. She wins the next four matches and the tournament. She moves on to Madrid and runs the table, then travels to Paris and wins her first two French Open matches before finally yielding after 13 straight victories on clay.

Three weeks later, she defends her 2017 title on grass in Birmingham, England. It is Kvitova's sixth tournament win since her comeback from the attack and her fifth this season. Now ranked seventh in the world, she has vaulted firmly into contention for a third Wimbledon championship.

The rectangular green jewel box of Centre Court is never far from her mind. The first thing she asks Radek Kebrle, the surgeon who operated on her hand, when he visits her bedside the day after her four-hour surgery, is: Pane Doktore, pojedu na Wimbledon?

Doctor, will I go to Wimbledon?

"At the moment, I thought, 'You are crazy,'" Kebrle says later, almost whispering the word. "Your injury is so difficult. We're talking about if I will be able to brush my teeth and do all my things and use my hand, and you want to ask ... of course, I understood the question. And I told her, 'We'll do everything to get you there.'"

But Kebrle doesn't sugarcoat it. Ten percent, he tells her: that is his estimate of her chances to come back at the elite level. Rehab will be slow and hard, and he will need her full concentration and cooperation.

She waits until he leaves before she allows herself to cry. And then she grabs the slim lifeline he has cast in her direction and refuses to let go.

Kvitova seems to have emerged from nowhere, fully formed, when she is named WTA Newcomer of the Year in 2010. Mere months later, she upsets Maria Sharapova to win the 2011 Wimbledon championship as her childhood idol, Czech-born icon and fellow lefty Martina Navratilova, applauds from the stands.

In fact, Kvitova's early career is less observed than many. Western reporters wrestle with the consonants in her last name -- pronounced KFIT-oh-VAH, three syllables, please, not Kah-VIH-toe-vah -- and her unlikely, uncommonly quiet backstory.

It takes more than three hours to get from Prague to Kvitova's hometown of Fulnek (pop. 6,000) on the country's perpetually congested highway system. A castle perches in the hills above a small commercial district that includes a household appliance company where her mother, Pavla, once worked in the purchasing department. Her father, Jiri, a retired teacher, spent his spare time hitting with his sons, Jiri and Libor, and their much younger sister on the town's clay tennis courts.

It's easy to see how her father's passion and her mother's composure merged in Kvitova as her parents sit in the kitchen area of a new, two-story clubhouse completed last year, overlooking four clay tennis courts. Petra donated the money to build the clubhouse, and her junior trophies sit atop the cabinet that holds cups and saucers.

Petra sprouts early and slender and gifted, but her parents don't have the money or the inclination to send her away to hone her talent. School is the priority, and there are days when she has time to play for only an hour. By age 16, she stands out enough to be spotted by a scout from the regional tennis center in Prostejov, about an hour away.

Jiri Kvita, a big-framed man with salt-and-pepper hair who shares his daughter's penchant for self-deprecating humor, does most of the talking through an interpreter while his wife takes in the scene with her steady, brown eyes and adds an occasional detail.

"It's hard when your child leaves,'' Jiri says. "It wasn't until she was 16 that she went [to Prostejov] occasionally, and it wasn't until she was 17 that she stayed.'' They insist that she finish her last year of high school via independent study even as she begins to travel. Years later, at the most uncertain point of her post-attack recovery, she taps into an old habit and enrolls in a university course.

Kvitova thrives in Prostejov, where many prominent Czech players have come of age. The complex includes a stadium with a retractable roof, multiple outdoor courts, a gym, dorms and a restaurant. It is one of many arms of the Czech tennis industry presided over by Kvitova's early patron and Czech business manager, Miroslav Cernosek, whose company also owns the Prague tournament.

“I'm happy that I have all my fingers, at the end of the day.” Petra Kvitova

At age 21, after uncorking an ace to put away Sharapova at Wimbledon, Kvitova is still unaccustomed to the spotlight, especially when it includes a microphone. Her voice shakes as she speaks on court during the trophy ceremony. At the champions' ball, pressed to say a few words, she tries to describe her thoughts on match point: "I have a chance now, and you never know if it will be more or no. OK, you have to do it, and I did it.''

Katie Spellman, then working in communications for the WTA, watches and listens. She has seen Kvitova interact with the Czech press and knows she loves to banter. Once she becomes Kvitova's public relations manager in 2012, they work at bridging the language gap. Spellman gives Kvitova a copy of the children's book "The Secret Garden" to broaden her vocabulary and shows her transcripts of postmatch interviews by Sharapova and Roger Federer.

By the time Kvitova wins Wimbledon again in 2014, she is able to speak with far more fluidity and nuance. She now routinely laces answers with idiomatic English. "What is the key to playing well on clay?'' she repeats in response to a question this spring. "Tough to say. If I know the key, I would already use it."

She wears her fame more easily now as she walks through public spaces, unmistakable at 6 feet tall, with stylishly tousled blonde hair that she pulls back into a thick braid when she plays and a pale, blue-eyed gaze that can be almost disconcertingly direct.

Her father asks the reporters who have come to Fulnek to let the world know that he and his wife are "not haughty, greater-than-thou types." He is the one who cannot contain his tears when Petra wins Wimbledon for the first time, his face working with failed effort, while Pavla smiles serenely at her daughter.

His face crumples briefly with a different emotion at the memory of the morning they learned Petra had been attacked. "Horrible,'' he says hoarsely. "When we say, 'Happy Birthday -- I wish you a lot of luck and a lot of health,' it's no longer a cliché for us."

Her family's small-town humility remains at Kvitova's core. As the coffee break at the InterContinental winds down, she offers to pay (and is rebuffed), then won't leave the table until the check is signed, not wanting to strand the interviewer by herself.

Following the attack, Kvitova's fellow WTA players -- who voted her winner of the circuit's sportsmanship award for grace on and off the court six out of the past seven years -- fill Twitter with paeans and blow up her phone with supportive messages. When world No. 1 Simona Halep breaks through to win in June at Roland Garros after falling short in three previous major finals, she reveals that Kvitova had sent her private notes of encouragement: "She said it's gonna come. I just have to keep working."

The goodwill that envelops Kvitova makes the events of 18 months ago even more unfathomable.

Alone in the backseat of a hired car on that December morning, facing a tedious, 145-mile ride to a specialized hospital north of Prague where Kebrle, one of the foremost hand surgeons in the country, is expecting her, Kvitova doesn't dwell on "why me?" There is only "what now?"

Her wounds have been disinfected and swaddled in a cooling wrap at a local hospital in Prostejov. She and her brother Jiri have gone back to the flat where she was attacked to gather a few personal items and the Christmas gifts she bought for her family. When they close the door, she is resolved never to return.

Kvitova's mind tunnels into a place where she is in control. She has obligations. She has already contacted Cernosek, whom she was supposed to join at a charity event that day. He arranges for the car she is in now and the security guard who will be posted by her room after the surgery. There are other people who need to know. She is a celebrity, and the news will leak fast. One-handed, she hits contacts on her phone, taps out texts and records voice messages. A part of her is in shreds, but her mind is clear.

She reaches Marijn Bal, her agent at IMG, at 4:59 a.m. ET and tells him, through tears, that she is not going to be able to play in the Australian Open next month. Bal thinks she is referring to a previously diagnosed stress fracture in her right foot. It's OK, he says, let's get healthy. No, she says, something just happened.

She confers with Bal in Florida, Spellman in Toronto and Czech tennis press officer Karel Tejkal in Prague. She tells them what she wants. They will post statements she helps shape, saying she is "shaken" but determined. She wants to speak to the media as soon as she's released so she can spend the holiday in peace with her family. Her fitness trainer, David Vydra, will meet her at the hospital, along with her good friend, doubles specialist Lucie Hradecka. She tells everyone else to stay home, that she will be fine.

"I've seen Petra cope with nerves that would put anyone else in a dark room trembling in a corner,'' Spellman says. "She was so nervous before the 2014 [Wimbledon] final with Genie Bouchard, and then she won in two sets, and everyone saw what she did with those nerves.

"I guess when you're a champion, and you're able to cope with all those emotions on the court and stick to your processes -- that's a big part of what players are taught to do -- she was able to apply that. She was the protagonist, and everyone else followed her lead.''

Twenty minutes after Kvitova arrives, Kebrle surveys the damage in the operating room. The knife has done its worst on her left index finger, which is slashed to the bone and hanging loose at the last knuckle. Seven flexor tendons, which give the hand its prehensile grasping ability, are severed in her fingers and thumb, their ends separated like snapped rubber bands. The ulnar digital nerves of her thumb and index finger will have to be repaired. There is no guarantee that she will ever regain feeling there.

Kebrle takes his time with the multiple incisions and uses suturing material that will dissolve. He inserts a pin in the finger that was nearly amputated. Because Kebrle treats other tennis players for various hand and wrist ailments, he is hyperaware of where they develop blisters and calluses and where scar tissue will be most problematic. He tries not to leave any more than he has to.

He does not sleep well that night.

"I knew who I am treating, I knew her needs, and I knew she is in a very big danger of not coming back,'' says the shaggy-haired Kebrle, a 20-year veteran in his field with a kindly face and a frank manner. "I said I was afraid of my own ass because at the end if she does not come back, everybody will connect me: I was the one who finished the career of Petra Kvitova.

"The trouble with this injury is you have to treat it, and then you have to mobilize it from day two, day three. You have to try to move the tendon, but you cannot pull on it, so it doesn't rupture. And the wound -- it wants to have rest for healing, but you must mobilize it. So it's a kind of slalom in between."

On the second day after her surgery, Kvitova places her right fingertips on her left fingers and gently, incrementally, begins to press.