Dear Frank Einstein,
Blue's death has been sad, yes. I'm proud to call you dad. Thank you for savin Twilight also. I am sure your marriage was beautiful.
On a side note, my sister has broken out of her insanity and is now princess again.
The reason I am writing to you is due to a threat we recieved. Somepony is trying to destroy Canterlot. We have Shining Armor protecting the city with his spell at the moment, but he needs scouts.
As of now, we have Areceus going farther out accross the sea. Trey and Will are checking the Everfree forest. Our greatest fear is that the very threat is already residing in Canterlot. We would like you to work under cover in Canterlot, seeing that your power is exponential.
We believe this may be the works of Foundervek, so watch out for imposters, mainly stalions. I will talk to you more in my dweling after you talk to Shining.
It is vital that you are unrecognized. Not even Twilight can know you are there. Stay 100% incognito.
Thank you for your help
Your loving daughter, Princess Luna