Task: Story Composition
Input (English): Premise: Zack's son wanted a bike for his birthday. 
 Initial Context: But he knew he couldn't afford one. 
 Original Ending: While Zack waited at a bus stop one day, he saw a bike with no lock. So he grabbed it and took in on the bus with him. When Zack's son got the bike for his birthday, he was ecstatic. 
 Counterfactual Context: Zack's sister had promised to help him with the costs.
Output (English): While Zack waited at a bus stop one day, he saw a bike with no lock. So he grabbed it and took in on the bus with him. When Zack's son got the bike for his birthday, he was ecstatic, but he felt guilty for stealing the other bike.