On November 6, 1942, Bernie Sapir wrote the last lines of his diary. Under the heading, "A letter to my darling," he wrote the following to Alice, the girl he'd met the previous winter: "In closing, I'd like to address a few words to you directly. It's been almost four months since you left me, four terrible months that have been dark and difficult for all of us. My darling, I have to be...