But once Prof asked, Mike tackled Warden’s top-secret messages. He had to start from scratch; in past Mike had erased Warden’s messages once transmission was reported. So slowly, slowly he accumulated data for analysis—painfully slow, for Warden used this method only when he had to. Sometimes a week would pass between such messages. But gradually Mike began to gather meanings for letter groups, each assigned a probability. A code does not crack all at once; possible to know meanings of ninety-nine groups in a message and miss essence because one group is merely GLOPS to you.