Imagine you find yourself in a situation where you prepare yourself to go for a visit of your friends that you haven\'t visited a long time ago. They live in a new town, have a new flat and you hardly wait for the gathering again. And because you don\'t really know where their new apartment in the big metropolis is, you decide that it is the best thing for them to wait for you at the rail station.And, now the mystery begins. You are looking for them, go through thick and thin, through every meter of the station, of different doors end entries. Of course, you will find your self very much worried.That is what happened to our friends today. Donald, Sandra and Mark live next to the Railway in their city, where their friends were supposed to arrive from another city. Half an hour ago their friends called them that they are coming, but when they arrived at the place, Donald, Sandra and Mark weren\'t on the Railway station. Now, they are worried and begin the pursuit for their friends. They really need your help so badly.