Timmy Barnes, his best friend Anna, and the five members of Bear Company have reached their toughest challenge yet. Before them lies a tall and treacherous mountain that they must cross over if they ever hope to get to Timmy's father and free him from his underground prison. Though it seems impossible, they have help in the form of the Alpine Rangers, a special unit of the Dark Corps made specifically for mountain-climbing. Even so, it's no easy feat, and it's made all the worse by fighting and arguments amongst the group of what they should do next. If they're not careful, they may not make it over the mountain--especially since a bizarre and unnatural force called the Whispering Wind stalks the peaks, waiting for climbers to scale the cliffs so it can tear them down into the darkness.