A young ATV rider and his friend set out to solve a race-day mystery in this action-packed installment of the Jake Maddox JV chapter book series. Teen ATV riders Josh and Christyna are revving up for a big race. Unfortunately, someone has sabotaged the trails, putting the safety of ATV racers--and mountain bikers--in jeopardy. Josh suspects his archrival, Adam, but he needs proof! Can Josh and Christyna dig up the dirt to solve this ATV mystery, or will the ATV motocross culprit leave them in the dust? With fast-paced text and extreme sports action, this installment in the best-selling Jake Maddox JV series is the perfect, attention-keeping read for young gearheads and sports fans.