Doors Trilogy

An action-packed mystery adventure by Germany''s Number One bestselling author: choose your adventure when you open DOOR ?, DOOR ! or DOOR X. This omnibus edition includes Doors ? Colony, Doors X Twilight and Doors ! Field of Blood.

When his beloved only daughter goes missing, millionaire entrepreneur Walter van Dam calls in a team of experts - including free-climbers, a geologist, a parapsychologi...