Dear Mrs...?Professor...What the bloody hell do I call you? Minerva McGonagall,
I am absolutely honored that Albus Dumbledore wishes to meet with me. Unfortunately, I will have to decline, lovely. As you know I have a book debuting within the next couple of weeks, which is filling up most of my scheduling. I hope you understand and that this invitation still stands once I find more time on my hands.
Besides, that loony old bat refused my request for interviews during my sabbatical, why should I give him the time of day now?!