You are invited to join us all in solving a mystery. A man named Dow signed up for a mysterious clinical trial called The Abacus Project.  It uses advanced technology to explore the very nature of reality. Dow has written 18 letters describing his experience with this project. This is letter 4. Joining the Letter 4 mystery sleuthing team this week are the insights of historian Inga Clendinnen, and psychiatrists Jim Tucker and Bessel van der Kolk. Kind of. In an AI kind of way. Let's play.