anita brenner turned out to be the same kind of obsessive letter-writer pack right. all of her letters were in the university of texas, the great archives of the world. i was able to go on a traumatic day and see she had neatly kept hundreds of letters that my father and family wrote to each other in the 20s. i saw patterns, the anger that had gone on 60 years before i was on the planet that became stamped on us. it became our dna. >> anything that helped you get insight as to why so much of your brother's anger and passion into what you regarded as coo coo politics? >> that is an interesting question. it is hard. what i have learned is, i have written biographies, bingham family of louisville. we take a letter of a piece of evidence, there is a ah-huh, this anger daughter wrote a letter to her father. my grandfather working away in san antonio then adored this daughter, book dedicated to him. she was then gone up to new york and going to school at columbia. he wrote her a furious letter. >> your grandfather? >> yes. you have broken your promise and haven't been putt