You wake up inside a submarine, in the middle of the Atlantic Ocean, and you are only told on a sheet of paper to mark some very specific coordinates on the GPS. After that you should activate the automatic pilot that will take you to an unknown and perhaps dangerous place. The journey will last for about four hours of real time, they said on the paper, and you will be all by yourself inside the D22 submarine. Fortunately, the people responsible for your abduction and imprisonment have left you a variety of books, recordings of various musical compositions, and a game of chess, so that the monotony won’t get the best of you – the mission needs to succeed after all. But who are these people, and why have they chosen you for this task? What is the mission? Perhaps you will be able to find out the answers you seek inside the submarine, or perhaps not.