Task: Story Composition
Input (English): Premise: Martha had two cats. 
 Initial Context: Her cats were named Billy and Bobby. 
 Original Ending: One day Billy ran away. Bobby disappeared shortly after. Later that night Bobby brought Billy home. 
 Counterfactual Context: Her other two dogs were named Mimi and Milli.
Output (English): One day Mimi ran away. Milli disappeared shortly after. Later that night  Milli brought Mimi home.