While vacationing in the mountains with their parents, suburban twins Allan and Allison discover a complex treasure hunt revealed to them, clue by clue, on small printed cards placed in secret locations. In search of each new destination, the kids find themselves roaming through the big mysterious house of their uncle as well as around the oddly-named town of End Of The Road. As the the treasure hunt progresses, they are presented with more complex clues as well as challenges and danger. Along the way, they discover eerie new places, find new friends, make new enemies, and learn secrets about their family's past. Eventually a strange world that they never knew existed is revealed to them.