Task: Story Composition
Input (English): Premise: I waited outside my brother's house to pelt him with snow balls. 
 Initial Context: As a special treat, I put some ice into several of them. 
 Original Ending: After this ambush, I ran some errands, eventually going home. When I pulled up to my apartment I knew something was fishy. I walked to my door to find some granny panties hanging on the knob. 
 Counterfactual Context: It had been his favorite game since we were kids.
Output (English): After ambushing him, I ran some errands, eventually going home. When I pulled up to my apartment I knew something was fishy. I walked to my door to find some granny panties hanging on the knob.