Three crushed roses intiating violence, a cypher message, and the picture of a beautiful woman, known to be an international spy--that's what Harleston, gentleman and member of the Secret Service, found in a cab, deserted by all but the horse, sleeping between the shafts, at 1 a.m. on Massachusetts Avenue. And before dawn he was set upon in his own apartment. Mr. Scott knows how to tell a charming love story and arouse intense excitement at the same time.
and, because of its very simplicity, the most impossible of solution. Change the key-word and one has a new cipher. Any word will do; nor does it matter how often a letter is repeated; neither is one held to one word: it may be two or three or any reasonable number. Simply apply it to the alphabetic Blocked-Out Square and the message is evident; no books whatever are required. A slip of paper and a pencil are all that are necessary; any one can write the square; there is not any secret as to it. The secret is the key-word.
Harleston took a sheet of paper and wrote the square: