In the wilderness sport of orienteering, you have only three tools to guide you: a map, a compass, and your instincts. Frank and Joe have come to the mountains of Idaho to learn the game from a master, college champ Rob Niles. But on this particular course, the boys soon find that there's only one instinct that counts -- the instinct for survival.

A deadly trap has been set for Rob, and he and the Hardys are headed into treacherous terrain -- a land of rattlesnakes, rock slides, and pinpoint sniper fire. As they blaze a trail to the truth, their courage, resourcefulness, and strength will be tested to the limit. Because if they lose their bearings, they may just lose their lives as well!