One early morning in July of 1945, a group of Allied soldiers raided a rooming house full of Nazis in Munich. It ended in a ferocious gun battle. Or maybe this happened April of 1946. And maybe there weren’t Nazis in the house: maybe there were just some old women, knitting. And was there actually a gun battle? For the rest of their lives, two of the men who were there — a dashingly handsome undercover spy, and the world’s most famous harmonica player — argued about what really happened that night. This is part one of two episodes about memory, in which we try to get to the bottom of the mystery.