Davos 1917

After a mission with the Red Cross on the Western Front, nurse Johanna Gabathuler returns to Davos pregnant. While she is still in the delivery room, her father takes her newborn daughter away from her. To get her back, she will have to make a deal with German secret services.

During the traditional New Year's Eve ball, when the drama of war takes a break, Johanna must carry out a risky assignment as a spy. However, the situation becomes critical, putting the nurse and her family in grave danger.

Johanna and Ilse discover the meaning of “Mission H”. The nurse must then prevent a mysterious Swiss Army encryption device from falling into the wrong hands, but her sister becomes suspicious when she finds weapons and money in her room.