Marshall Kaper and his friends are ready for their next adventure: a backpack trip over spring break. Air-soft games in the back country? Fun! Run-ins with rattlers, bob cats, and bears? No problem! Rescuing a kidnapped pilot? All in a day's work! An encounter with the drug cartel? That's another matter! Find out how Mars and his friends avoid death at the hands of hardened criminals in this detective novel for middle-grade students.