Princess Cadence tries to legally change her name to "Princess Cadance". Footnotes ensue. Part of the "Cadance of Cloudsdale" cycle, and a crossover with Ghost of Heraclitus's Civil Service stories. Familiarity with neither is required.
Princess Celestia had been going to spend the evening in a royal mope, but Pinkie Pie has other plans for the night, plans which involve piercing the walls of time and space with her most ambitious birthday greeting yet.