Britney Spears: In the Zone is a busy batch of Britney-mania, much of it featuring Spears in crisp dance numbers supplemented by behind-the-scenes glimpses and chatter. The heart of the show is an ABC television special featuring live performances of “Toxic,” “Breathe on Me,” and “I’m a Slave 4 U.” A fun highlight is Spears’s hip-hop collaboration with the Ying Yang Twins on “(I Got That) Boom Boom,” one of the few numbers in the star’s stage repertoire with a little room for spontaneity. Between songs one finds Spears gushing over her grandfather, praising her entourage, describing the emotional toll of being in the public eye, and writing songs.