It is snowing, and 16-year-old Carlotta is standing on the vast military training ground in Grafenwohr watching a howitzer 2000 fire live ammunition. It is cold and very loud when the shells are fired, so Carlotta has to wear earplugs. This is not a day like any other for the young school student: While her friends are sitting in warm classrooms in Cologne, she has made her way to Bavaria by train alone.