Check the baggage office.

Standing at the baggage claim, Katie waited...and waited... The carousel shut down. She never saw her bag. "Dammit."

Katie walked round the set-aside baggage. Nothing. She went to the airline baggage office. Inside were a young man and a woman standing at the counter, having an intense conversation with the clerk. The young man was wearing a hoodie and a hipster beard and glasses. The woman might have been a bit older, with a figure like Katie's curvy one, but with a mass of dark, curly-wavy hair and wearing a brightly embroidered jacket.

The bag by the young man's knee was the same model as Katie's, and the tag showed the same flight number as hers.