A thousand years ago Nightmare Moon fought Celestia at the castle of the two royal sisters. The destruction was devastating. Wild magic and falling stonework were too much for the pregnant mare to escape. Her dying wish was her foal could be saved. Sometimes wishes get answered in the most unexpected ways.

The Tantabus acted with a mind of its own. It had a goal, it had its own desires, it took the form of a unicorn, it wanted to live. The reason why will change Princess Luna's life.