Identical letters are addressed to each man and delivered by school owls
I understand that you have been preoccupied of late, however, I have a proposition for you and would like to meet with you this coming Wednesday after classes have ended. We will take tea in my office at 4 p.m. If this time is inconvenient for you, let me know. Otherwise, I will see you then.
Minerva McGonagall Headmistress Hogwarts School for Witchcraft and Wizardry