- "You'd better make sure and check what's in your briefcases."
"Er, well, I had cheese and pickle sandwiches in mine!"
"My sandwiches have ham and mustard!"
"So that's what the Really Important Luggage is!"
- ―The lost property officer, the travel agent, the banker, and Thomas' driver
Really Important Luggage is a magazine story.
Thomas and his coaches wonder what is in the important-looking passenger's briefcases. Later, a man at the travel agency cannot open his case and at the same time a banker cannot open his, either. At lunchtime, they both go to Elsbridge's lost property office and find that they have accidentally taken each other's case. They open them to make sure and Thomas, Annie, and Clarabel find out what they keep in their cases - their lunch!