Task: Question Answering
Input (English): Few of the puffs still resided on Popstar but many left to who knows where . " Those poor lost souls ... " The knight thought to himself . He remembered falling ... falling from the sky .... The sky was so deep and dark blue ... the stars were falling . The other puff creatures were'born'this way , too . Metaknight remembered how they fell like stars .
Output (English): What may have caused the puffs to leave Popstar ?