The Riddle

Twilight Sparkle,

It is because I have been informed of your intentions by my beloved sister that I feel the necessity to share with you the following: I have once had an interaction with a phoenix, and whatever has taken place that day has led to the erasure of all of my memories of the incident, leaving me knowing nothing beyond what I have just written.

Alas, there are a great many secrets that could be unveiled by somepony brave and powerful enough to step onto this route. I do not seek to discourage you, merely to advise caution, particularly if you are to come close to that which shapes the very nature of this mysterious species.

Respectfully,
Princess Luna.
Ruler of the Night and the Realm of Dreams

PS: I do hope I did not fail on the technicalities of a casual letter.