Series: The Rhythm of Time

It's not easy being a teenager, and it's no different for Rahim, who is trying to balance everything in his busy Philly life: school, parents, bullies, his secret hopes of becoming a hip-hop star, and the constant schemes of his brilliant best friend, Kasia. When Kasia invents a new kind of cell phone that is also a time machine, it...

On the heels of their thrilling appearance in The Rhythm of Time, best friends Rahim and Kasia are back in Time for a Change. Last time around, they were on their own—now they are working with a mysterious organization from the future that tasks them with averting disaster and safeguarding the flow of history. The first assignment sends Rahim to...