Liam, Maddy, and Sal are TimeRiders, teens who've been saved from certain death to prevent time travel from destroying history-and the future. But when Maddy mistakenly opens a time window, Liam is marooned sixty-five million years in the past, in the hunting ground of a deadly species of prehistoric predator. Liam's only hope is to make contact with Maddy and Sal before he's hunted down by dinosaurs, and without altering history so much that the...