Of course, our next order of business is to learn exactly what this mysterious event is. I'm glad it's not a gala. A gala would be extremely cliche. Andromeda is probably right that it's some sort of ceremony.
Of course, we start at the library. I look in the history section and Andromeda looks in the politics section. I find multiple books about ceremonies, religious and otherwise. From the tables of contents I find that there are a lot of ceremonies in a lot of different cultures surrounding the spring equinox. I telepathically ask Andromeda, "Can you help me narrow my pile down?"
"Only if you help me narrow mine down."
I walk over to Andromeda, who's carrying a stack of books as tall as mine. We lay the books on a table and start turning to the applicable chapters.
In Andromeda's stack we find the characteristics of the type of ceremony we're looking for: one that reinforces the status quo. It doesn't take long to find a match in my stack.
The Festival of Eridanus
The Festival of Eridanus, or the Festival of the River of Stars, was a reaffirmation of loyalty to the current monarchs.
The festival took place at the Spring Equinox and involved various performances and festivities, culminating in the newest knights making a declaration of loyalty to the monarchs.
I show Andromeda the excerpt and she agrees that this is exactly what we're looking for. "There's a description of the ceremony near the end of the chapter. I'll be able to make my plan from there."