Johanna, a young nurse, returns to Davos pregnant after a Red Cross mission. Despite wanting to keep it, her child is taken away from her after she gives birth.

Johanna works as a spy during the New Year's ball and gets closer to someone with a dark secret. However, she eventually finds herself in danger when things don't go to plan.

Johanna learns what Mission H is about and has to find a way to keep the Swiss army's coding device out of enemy hands.

After Taylor's departure, Johanna's position deteriorates. Ilse has to eliminate her, but doesn't account for Johanna taking precautions.

Johanna receives an assignment, the success of which could have a significant impact on the outcome of the war; Ilse makes Johanna an offer, but she falls into a trap.

Johanna and Dr Mangold come up with a plan to finally escape the war. However, Mangold's escape attempt is thwarted.