What happens when Katrin goes to the train station on the day of the trip?

At the Train Station:

• The day of the trip is warm and sunny.
• Katrin arrives at the train station early with her entire class.
• She spots a boy standing further away, watching her attentively.
• She realizes it is Frank and intends to call out to him.
• However, at that moment, Frank runs away.

Summary: Upon arriving at the train station, Katrin sees Frank observing her, but before she can react, he unexpectedly runs off.