"The McNallys run into an early snowstorm in Colorado. They stop at a lodge for the night and by morning, they are snowed in! While looking for a place to study, Gavin and his sister, Chloe, accidentally go through a door into a dark hallway. And the door locks behind them! It's getting colder by the second. Will Gavin and Chloe have to weather the blizzard in the dark, frozen passage?"--Provided by publisher.