Luna is growing lonely. The only pony to talk to really, is Celestia. But she was always busy and Luna didn't want to bother her. She wanted somepony to talk to. A best friend.

As Princess Celestia's younger sister, Lullay, is shadowed by all of her glory, she feels that the sun is threatening the moon's balance. She steps up to her sister and instead of protecting the moon, she overtakes the sun.