By Alex Tresniowski
March 19, 2007 12:00 PM

Serena Williams stands at the Door of No Return, between her future and her past. Not long ago she was the best female tennis player in the world, but on this day in November 2006 she seems all but finished with the sport—she hasn’t won anything in two years, hasn’t even played a match in months. She is far from home on the west coast of Africa, on Senegal’s remote Goree Island, a former trading post from which slaves were shipped to the Americas and the Caribbean. Standing at the Door “all you see is the Atlantic Ocean, and it was just mind-boggling to think about what my ancestors went through,” says Serena, 25, of her pilgrimage to Senegal’s House of Slaves. “That just changed me. It gave me strength and courage, and it let me know that I can endure anything.”

Just a few weeks later Williams stunned the tennis world when—ranked a dismal No. 81 and nowhere near peak physical shape—she somehow beat six seeded players and demolished current tennis darling Maria Sharapova to win the Australian Open on Jan. 27. “It’s one of the most improbable things I’ve seen in tennis, and one of the most heartwarming,” says CBS analyst Bud Collins of Williams’s win, which followed a four-month sabbatical from competition. “Nobody took her very seriously, but she shot the moon. It was a victory of heart and guts.”

More important than her eighth grand slam title was the journey that preceded it: Williams dealt with lingering grief over the death of her sister Yetunde in a 2003 drive-by shooting, weight issues and feelings of depression before emerging from her time off “as a different person,” she says. “I went through a lot and when I came back I was ready.” Serena’s long layoff “refreshed her mind, body and soul,” says her mother, Oracene Price. “It was a spiritual awakening. She was defining who she is and being happy with it.”

Since turning pro in the late ’90s, Serena and her sister Venus—raised in hardscrabble Compton, Calif., and taught to play on concrete courts by their father, Richard—won tournaments by the bunch. Serena, in particular, dominated the game, holding a No. 1 ranking for 57 straight weeks. But by 2003 the sisters had been slowed by injuries and outside interests. Serena kept competing through knee pain until, last September, she walked away from the game she’d been playing since age 4. “A lot of my sponsors weren’t too happy,” she says. “My personality is to try to please other people, but I learned I have to make myself happy.”

First order of business? Sleep in and watch tons of HGTV. “I stayed in bed until 10, which I’d never been able to do before,” she says. Yet she found that when she stopped pounding countless tennis balls she lost an outlet for her emotions, forcing her to confront the anger she still felt over the random murder of her older sister. Last April Serena spoke at the sentencing of the shooter, an alleged gang member who received 15 years in prison for the crime. “I don’t think I ever really grieved the right way,” she says. “It’s still hard for me to talk about. Yetunde and I were so close; she changed my diapers. But I finally came to an acceptance of things.”

It was during her time away from tennis that Serena first faced her feelings of depression. “I’m an emotional person; I live on my emotions,” she says. During her break “I was going through so much and it was a lot of feelings coming up. Some days I’m still depressed.” Serena won’t say exactly how she manages her low points, but the trip to Africa—her first—helped. Besides visiting Senegal she traveled with UNICEF to poverty-ravaged villages in Ghana, giving children malaria shots and helping string mosquito nets. “The kids were so gorgeous, it broke my heart,” she says. “Now I’m just trying to get other people to realize what’s going on there.”

Late last year, Serena began training for her comeback. That meant cutting out the Starburst candies she loves and resuming her usual regimen of running and yoga. Even so, Serena entered the Australian Open with something other than, well, the typical tennis body. “I know, I know, I have a big fat butt and big boobs and there’s nothing I can do about it,” she says. “Generally, guys like butts and boobs, so it’s not an issue for me.” Nor did it slow her down on the court, where she buzz-sawed her way through a tough field. “I’d set my alarm for 3 a.m. and get up and root her on,” says Venus, who is nursing a wrist injury and watched her sister’s magical ride on TV. “I’d call her with tips about players, but really I just didn’t want to jinx her.”

Now it’s her competition that might be feeling cursed: Although Serena is still juggling plenty of outside interests—including fashion (like Venus, she has her own clothing label), playing guitar (she looooves Green Day) and acting (she’s had parts on Law & Order: SVU and ER)—she insists that “tennis is still the main thing in my life.” That, and “a special friend who means the world to me,” says Serena, who is otherwise coy about whom she is dating. As for her constant companions—Laurelei, a cuddly Maltese, and Jackie, a live-wire Jack Russell—”Jackie’s the alpha dog, she’s in charge,” says Serena, who lives in Florida. “I need the Dog Whisperer.”

Whether or not her win Down Under propels her back to alpha status in tennis (she’s now ranked No. 15), what she’s learned about herself in the last few months is, she says, reward enough. “I am totally on my own now,” she says. “I’m always going to just be Serena.”