Emanuella "LL" Harvey puts her gymnastic skills to good use as a member of her brother's Parkour group. Free running, jumping, and climbing over their corner of the city like it's an obstacle course gives them something to take pride in and keeps them out of trouble—sort of. But trouble finds LL when she runs into Haze, a talented graffiti artist whose sister Heather was murdered two years before.

Freerunner and Writer promptly fall in love, but they decide to hide their relationship till they're sure it's the real thing—and until they can find a way to placate LL's hotheaded brother, who has it in for Haze and his gang. But when portraits of LL done in Haze's distinctive style start popping up on city walls, all hell breaks loose.

LL's brother threatens a gang war, which LL tries to avert by identifying the Writer who is really responsible for the paintings. But when another teen is murdered, it looks bad for Haze, especially when LL discovers that Heather's killer and her portrait-painter are one and the same.