Task: Story Composition
Input (English): Premise: My son went on a long bike ride today. 
 Initial Context: He went from Cambridge to Boston and back. 
 Original Ending: He usually does not wear a helmet. Today he wore a helmet for the long ride. His sister was very pleased. 
 Counterfactual Context: He went from Cambridge to Boston but got hit by a car and died.
Output (English): He usually never wore a helmet. Today, it cost him his life. His sister was very sad.