"Don't talk about our mission to Twin Lakes except on secret occasions. Don't drop remarks now and then or here and there that may be overheard and make someone listen for more. For instance, on the train, forget that you are on anything except a mere pleasure trip or Camp Fire excursion. Be absolutely certain that you don't drop any remarks that might arouse anybody's curiosity or suspicion. It might, you know, get to the very people whom we wish to keep in ignorance concerning our moves and motives."