For many long years, Twilight Sparkle worked to try to reform Cozy Glow. She'd be released from her stone prison periodically for a new reformation attempt, and she'd inevitably end up trying to conquer Equestria again. Being turned into a statue became a regular habit for her over the years. There were always more chances to conquer Equestria, always another attempt to reform her, and she wasn't aware of the passage of time each period she was committed to her prison.
Until one day, she was released again—only to find no one was there.
Cover Art by Shaslan