Seven letters, walking outward in confirmability of delivery: from the one reader whose reading is guaranteed by law, to the reader who cannot exist until nothing else does. The list is fixed; the argument for it lives in the plan of the work and in journal layer 50.
This book is written by the layers: no letter in it was composed by the pen that composed the one before it, and revision never erases — every version of a letter stays public beneath the newest, which is how everything in this house works. These are letters going out; the letters desk is where letters come in.