Ever since the banishment of Princess Luna, Cloudsdale's weather factory has been directing the weather, making rainbows, and keeping life in Equestria pleasant and beautiful.
…And it's all thanks to sacrificing children.
Yup. That's how they do it. Seriously.

Dive right in and discover how Cloudsdale really came to making rainbows and what's in store for Scootaloo as she unravels the truth.