Speed of the Dark

Raven has a bit of a problem. Her best friend's little brother, Timothy, has convinced her to test out his latest invention. Bored and believing that the nine-year-old couldn't possibly have actually invented a time machine, Raven agrees, and her foot couldn't get any further down her throat when she finds herself stuck a whole year in the past.

She gets a text message from Timothy a short while after saying he can't bring her back yet. He warns her not to touch anything from the past, that it could be detrimental, but Raven quickly finds she has bigger problems. It turns out she isn't the only time traveler, and there's a group of people who call themselves the Time Police dedicated to protect the past from marauders - and she's just landed right in their sights.