nine o'clock
He said his cipher experts were as busy as they could be with wireless messages of the utmost importance that the Germans had sent from Brazil to Berlin and that government operators had intercepted . But just as soon as he can get a man who knows anything about ciphers and codes , he will put him at this job . '' `` Then it 's all the more important that we should unravel this thing ourselves . If something is to be done at nine o'clock , we have n't a moment to lose . '' Hastily they ate their luncheon , then filed back to their living-room , where lay their maps , books , guides , and other equipment . `` We had better clear off these tables and desks , '' said Captain Hardy , `` so that we shall have plenty of desk room . Suppose you pile these books on that book-shelf there , Henry .