Celestia had always assumed that the relationship between Ponies, Dragons, and Changelings would be fraught with conflicts, no matter how much crystal peace there was. However, everything would change in a meeting where she would discover something very relevant, something they all have in common that would unite them in a single mission together...

"Now... How is it that you two know Spike?"

(Nope, Triple Threat is not canon here...god i hate that episode)