Task: Story Composition
Input (English): Premise: Timmy was about to return his library books. 
 Initial Context: He went over the list of books and noticed he was missing one. 
 Original Ending: The book was a novel that was a hardcover. He searched everywhere in his house. Finally he remembered he left the book at a friend's house. 
 Counterfactual Context: He went over the list of books and returned them all.
Output (English): The books were a series that were hardcover. He searched everywhere in his house before he returned them. Finally he remembered he left the book at a friend's house.