The one before the BIG one. Johnnie Walker returned for our 50th about a week early so that we could have a great week long visit. I'm glad we did it. When Bouncing Bill picked him up to drive him to the airport it would be that last time we ever saw him. WE recorded a session before the 50th. Since we were at Session 599, it seemed to make sense to record so that the 50th was Session 600.