Task: Story Composition
Input (English): Premise: Billy has a sack full of rocks. 
 Initial Context: He carried them around all the time. 
 Original Ending: One day he pop one in his mouth and ate it. His mom was worried he did something horrible. It was rock candy he bought at the store. 
 Counterfactual Context: He carried them to the trash and threw them out.
Output (English): One day he got another rock and popped it in his mouth and ate it. His mom was worried he did something horrible. It was rock candy he bought at the store.