Joey pressed so hard upon her eyeballs that she saw violet stars instead of handkerchiefs, and then, in the midst, she saw again distinctly those funny little marks which had shown themselves between the red-worked initials of the Professor's name, --.--...-- Dash, dot, dash, and dot, dot, dot, dash--that was Morse, and it spelt two letters, K and V. What could they stand for? The Professor's name was Achille, so he had informed Noreen, when, greatly daring, she had inquired one day a week or so back, after a particularly peaceful "stinks" class, when she had not been addressed as Fathead. Besides, what person in their senses would have a name first worked, and then fixed on in some kind of invisible ink, and in Morse? K V! K stood for Kenneth or Kitten or Kultur, or Kamerad, or Kaiser. (It was odd how many German words came unbidden to her mind.) And V might be Vauxhall or Vaterland! Yes, Vaterland was spelt with a V, though it sounded as if it were an F. Joey found that the two words Kaiser and Vaterland fixed themselves in her mind, and joined together with John's odd tone about the signalling, and the Professor's midnight expedition, and that lettering that she had read--the figures--31, and then the answer _Ja_. The 31st was to-day, and Ja, as Noreen had used it in the wonderful charade, meant Yes. What was going to happen to-day, and who had answered the Professor's signal? Joey's mind went back slowly over the ground of this exciting month at Redlands, till it reached that Sunday spent at Mote, when she had come back to school alone, and been caught by the sea-roke, and had taken shelter in the Round Tower. The jumpy young man had certainly been doing odd things down below, and he had not been at all pleased to see her there at first; that was certain, though he had been quite kind and nice afterwards, and told such interesting stories. It had never occurred to Joey that the stories might have been intended to have a deterrent effect upon her. But could the young man's obvious jumpiness have anything to do with the mysterious business? Noreen had thought so, but Joey hoped it hadn't, for if it were he who had answered Ja it meant he was a German, and she didn't want him to be that. It was much easier to think of the Professor as a German; Joey had rather liked the young man, in spite of a slight natural contempt for his nervousness. And then, quite suddenly it all came over her; a sense of some great danger, which was none the less frightful, but rather the more, because it was all so vague.