Two little girls, the same but different: skin an identical shade of brown—”as if one piece of tan material had been cut to make us both”—and small bodies confined to the grim council flats of early-’80s London, but minds flying toward a bedazzled, freewheeling future as professional dancers. Tracey actually has the talent; our nameless narrator does not. Her flat feet and leaden tempos only intensify her longing for Tracey’s grace, and a fraught friendship forms around their mutual love of movement, from the fluid Fred-and-Ginger waltzes they rewatch obsessively until the VHS ribbon warps to the impossible antigravity of Michael Jackson on MTV.

Tracey is formidable, a tiny supernova of willpower and charisma. But as Swing Time dips elliptically between the further and more recent past, she begins to seem like training wheels for another alpha female: Aimee, an elfin Australian pop singer with a Madonna-esque career trajectory and monstrous ego to match. Pulled into Aimee’s orbit by chance in her own early 20s, the narrator becomes her assistant, shaping a sort of liminal half-life around her A-list charge—”a person for whom I scheduled abortions, hired dog walkers, ordered flowers, wrote Mother’s Day cards, applied creams, administered injections, squeezed spots, wiped very occasional breakup tears, and so on.” When Aimee’s mercurial attentions turn to charity, the job gains another dimension: traveling back and forth to an unnamed African country where the goal is to set up a girls’ school, eradicate poverty, and liberate the people, more or less.

Kinetic riffs on race and class, culture and privilege have been Zadie Smith’s signature since she first emerged at 24 with her star-making 2000 debut, White Teeth. Sixteen years on, her writing has mellowed; Swing Time doesn’t have the electric jolt of Teeth’s Technicolor rhythms, but it does offer more insight—an emotional acuity that radiates through a series of small, beautifully crafted revelations. What it can’t do is make the central character come fully alive, or even feel crucial to her own narrative as the story begins to list and wander toward its shaggy end. Though if you’re looking, there’s a warning right there on page 4: “I had always tried to attach myself to the light of other people…. I had never had any light of my own.” Without it, Swing Time‘s resonance, only half illuminated, slips away.