Interesting e-mail from reader B.G.: "I believe your skepticism regarding Lt. Col. Shaffer’s memory – 'whether the otherwise obscure name of "Mohammed Atta" might have become part of their recollections after the fact because it became so famous' – deserves your reevaluation. "I would contend that whatever Shaffer knew about Mohammed Atta and the Brooklyn cell would have been reinforced in, and not 'become part of,' Shaffer’s memory on and in the days immediately after 9/11. Other elements of the story, such as having three meetings to transfer this information cancelled at the last minute, and the resulting feelings of...