Door

Alex eased his pack to the ground and looked around the empty campsite-the last known location of his friends, 57 hours ago. 

On a mountaineering expedition gone awry, Alex and his friends stumble upon something they never expected to find: a mysterious door hidden beneath a glacier. Driven by the excitement of discovery, Alex''s friends are determined to return, but they are not the only ones who are interested in what the door might contain. When his friends go missing, Alex will have to brave the dangers of the mountain, evade the Historical Acquisitions Agency, and use all his wits and resourcefulness if he is going to unlock the secret of the door and find a way to bring his friends home.