Britney Spears
Credit: Michelangelo Di Battista

Late this past fall, cover story writer (and InStyle's Fashion Features Editor) Isabel González Whitaker went out to L.A. to interview Britney Spears, just as the singer was gearing up for her two-year Las Vegas show, Britney: Piece of Me. During an extended break, Spears sat down to answer reader questions and was impressively candid and in control. The following is an excerpt from the article, "American Idol," published in InStyle's January 2014 issue, available on newsstands and for digital download now.

In a dance studio in an industrial area east of Los Angeles, Britney Spears is rehearsing for her lavish Britney: Piece of Me show, which is set to debut December 27 at the Las Vegas Planet Hollywood. The two-year gig, as she describes it, will be nothing less than wild: moving stages, glittering costumes, scores of hunky backup dancers, rain—and snow—machines. This space, however, is decidedly unassuming. Perhaps the only indication that something special, someone glamorous, might be inside the nearly windowless concrete block: two paparazzi stationed on the sidewalk beyond a tarred-over parking lot, positioning their long lenses through a wire fence.

The chorus of “Toxic”—“Of all my songs it’s my favorite,” Spears says later—blasts from a back room and into the tiny lobby, so loud the framed photos of ballroom dancers on the walls pulsate. After the chorus ends a choreographer counts off beats—“Five, six, seven, eight!”—and then it replays some 20 times more. Accenting the acoustics is the squeaky sound rubber-soled shoes make as they pivot across high-gloss floors. It’s hard to tell whether it’s one person—Britney?—or her 14 dancers back there. One thing is for sure: It’s sweltering, as if she’s determined to replicate Vegas’s desert heat as part of her boot camp. And then the song switches.

“Stronger than yesterdayNow it’s nothing but my wayMy loneliness ain’t killing me no moreI’m stronger.” —“Stronger,” 2000

This chorus gets just three plays, and that’s plenty of time to catch the message: It’s a resilience anthem if ever there was one. Spears may have made it a mega-hit 14 years ago, but the dance-pop song seems even more poignant now for the singer, who has managed to weather challenging times and make it back from the dark corners.

And boy, is she back: The 32-year-old has just come out with her eighth album, the very personal Britney Jean; the lead single, the whip-smart dominatrix ditty “Work Bitch,” topped the charts when it was released this fall. The 96-date Britney: Piece of Me show has her joining the ranks of Vegas legends in residence like Céline Dion and Elton John. Then there’s her family life, which keeps her happy and on track. Photos she posts on Instagram show her two smiling and playful boys, Sean Preston, 8, and Jayden James, 7, on family vacations, at birthday parties, and in kiddie-size car-racing gear. While she won’t talk about it or even mention his name, a nice-guy boyfriend also seems to be in the picture.

It’s easy to imagine that a Vegas performance of “Toxic,” or other iconic hits like “… Baby One More Time” or “Oops! … I Did It Again,” might unite fans in a frenzy of shared nostalgia. But nowadays “Stronger” is the sound-track to her life. It will have her devotees screaming along in solidarity, cheering on the pop star who can’t be stopped.

Soon enough it’s time for a lunch break, during which the singer will excitedly answer questions from InStyle readers. Spears, in her signature off-duty look (a fitted tank, cozy sweatpants, hair in a sweetheart topknot), strides into the lobby. Undistracted by the commotion of dancers walking past her, she heads into an adjacent bare-bones office whose single window is draped with hastily hung black fabric to keep out prying eyes (and lenses). She settles into a leather armchair and places her Starbucks iced coffee on the wooden desk. Sweat has smeared mascara nearly down to the tops of her cheekbones, a sign she’s been dancing for two hours straight with the temperature cranked high. If Spears is tired, she’s not letting on; she sits upright in the chair, takes a sip of her drink, and is ready to, OK, let’s say it, work, bitch.

For the full story -- where Britney talks about her killer bod, being a mom, and wanting a "mini-me" little girl -- pick up a copy of InStyle's January 2014 issue available on newsstands and for digital download now. Click here to buy or subscribe.