In this fictional criminal case, you have to find out the whereabouts of a woman from Cologne who has disappeared.

For a week there has been no trace of Karla S. An old school friend of the missing person has received a letter leading him to believe that she may have disappeared on purpose. But what is behind it? Can you help him to solve the mysterious disappearance?

Passing well-known and unknown places in the district, you will discover the secret. But don't make it too easy. The wanted person has camouflaged their trail well. At various locations you have to follow and collect clues and solve tricky puzzles that will gradually show you the way to the solution.

It may be that you play in a team with other people if more tickets are booked - and together you are smarter. Can you crack all the codes and solve the case as a team?