The mysterious YouTuber known by her fans as 'Sparkler' had been acting different. She had been sounding upset in her videos for a while, after a pony named Snowmint got murdered. Just when she started to cheer up, they stopped altogether when the culprit was arrested. What was her relationship with Snowmint and the murderer? And why does an alicorn cyborg Sunset Shimmer from another dimension randomly choose to investigate?