It has taken over a century, but Celestia has revived and cured King Sombra. His memories of their love fully intact, they decide to get married. They are happy together and happier for Luna and Discord who had started dating after the wedding.

Things don't stay that way for long though. Celestia starts talking about starting a family. Sombra is unsure, but agrees anyways. The news travels faster and just a few short days later, Luna and Discord break up.
The only one who knows is Sombra. He tries to be there for Luna, but in doing so is he jeopardizing his life with Celestia?