On page 390 of the first edition of MR.X is found the mysterious inscription:

P.D.10/17/58

This is Paul Desmond, in a bit of creative boredom before the concert described in the last pages of the book. And on page 450 of the hardback of MYSTERY there is seen "a dark wooden table on the surface of which a traveling musician had once scratched…”

PD 6/6/58

It is discovered by Tom and Lamont when they fly back from Eagle Lake in secret to Mill Walk and check into the St. Alwyn... Four months before the Edgerton date, a concert on Mill Walk.