Two elderly gentlemen from a Munich student fraternity disappear without a trace. The only clue to their whereabouts is an email containing coordinates. Dr. Engler, who is also a member of the fraternity, asks Alfred Sanktjohanser, known as Sanktus, for help. In a thrilling geocaching chase through Munich, the two try to rescue the victims and bring the murderer to justice. A life-and-death hunt begins.