Part 1. Definition
Given a premise, an initial context, an original ending, and a counterfactual context, the task is to generate a new story ending aligned with the counterfactual context and as close to the original ending as possible. Each instance consists of a five-sentence story. The premise is the first sentence of a story, and the second sentence, which is the initial context, provides more information about the story's context and the story's general plot. The original ending is the last three sentences of the story. Also, a counterfactual context is a slight modification to the initial context. You should write a new story ending that edits the original story ending as little as possible to regain coherence with the counterfactual context. To sum up, you should write the last three sentences of a story based on the premise(first sentence) and the counterfactual context(second sentence) of the story.
Part 2. Example
Premise: Susie was sitting on her barstool. 
 Initial Context: She kept kicking the counter with her feet. 
 Original Ending: Suddenly, her kick sent her falling backwards. The chair hit the ground with a thud and broke. Susie hurt her head and was really scared. 
 Counterfactual Context: She kept herself steady with her feet.
Answer: Suddenly, an earthquake sent her falling backwards. The chair hit the ground with a thud and broke. Susie hurt her head and was really scared.
Explanation: The generated new ending is perfect. It considers the counterfactual context and changes required parts in original ending.
Part 3. Exercise
Premise: Cyrus wrote a new song on her guitar. 
 Initial Context: She recorded the song on her computer. 
 Original Ending: The next day she played the recording of the song. The recording did not play correctly. Cyrus paid three hundred dollars for new recording software. 
 Counterfactual Context: She wrote down the chords on a paper.
Answer:
She mastered her song, and made a recording. The recording did not play correctly. Cyrus went and spent three hundred dollars for new recording software. 