Task: Story Composition
Input (English): Premise: There was a knock on Bob's door late at night. 
 Initial Context: Bob awoke and ran down to see who it was. 
 Original Ending: A man he never met before was pounding on the door and wanted in. Bob sensed a problem outside and let him in. The man collapsed on the floor as soon as Bob let him in. 
 Counterfactual Context: Bob grabbed a baseball bat and went to answer the door but no one was there.
Output (English): The porch was empty. Bob sensed a problem outside. He collapsed on the floor as soon as he closed the door.