What is Katrin's internal debate after seeing Frank at the train station?

Katrin's Internal Debate:

• Initial Doubt: Katrin questions if the person she saw was actually Frank.
• Certainty: She quickly becomes convinced that it was indeed Frank.
• Confusion and Questions: She is perplexed as to why he came to the station only to run away, especially since he could have waited for her.

Summary: Katrin struggles to understand Frank's actions, debating whether it was him she saw and then questioning his motives for appearing and then immediately fleeing from the station.