The first guess that Think-Tank made about the books found on earth was that they were sandwiches. He told Captain Omega that they were standing in a refreshment stand. He also said that sandwiches were the main staple of Earth diet. He then ordered them to eat one of the books. When Sergeant Oop ate it, he told them that it was not delicious, and that it was as dry as Martian dust. Then, Think-Tank suggested that the books were in fact communication sandwiches, and ordered them to listen to them. When they could not hear anything, he suggested that the books were not meant for ear communication, but for eye communication.