The Hardy boys and two friends take a camping trip to the Rocky Mountains in an attempt to locate a gang of credit-card counterfeiters.

The Hardy boys are chasing Whip Lasher, a practical joker. When Lasher leads them to vampire trail, the brothers have to get past the dangers that await them, but can they also get past Lasher too? 
This is one of my favorite Hardy Boys so far because it involved one of my favorite animals, Bats!

An assignment form their famous detective father to track down a ring of credit-card counterfeiters takes Frank and Joe Hardy on an exciting camping trip to the Rocky Mountains. But the cross-country trek with their pals Chet Morton and Biff Hooper is jinxed from the very first day. Strange happenings on a nearly impassable mountain lure Frank, Joe, Chet, and Biff to almost certain death before they discover the sinister reason for the danger on Vampire Trail.