As it happened, everything turned out most simply. Deirdre and Dulcie overtook Gerda farther on along the warren, and concluded that she had probably climbed up from the second cove by the same path as themselves. They discreetly ignored her red eyes and made some casual remarks upon the weather. The three were walking together when the rest of the school came up from salvaging. The head girl looked at them, but seeing that they formed an orthodox "threesome" made no comment, and passed on. She probably thought they had been taking a stroll on the warren. Gerda looked almost gratefully at her companions. She had evidently felt afraid lest they should mention the fact that she had not been with them the whole time. She made quite an effort to speak on indifferent subjects as they walked back, and was more conversational than they ever remembered her. At tea-time, however, she relapsed into silence, and during the evening nobody could draw a word from her. Dulcie woke once during the night, and heard her crying quietly. The two chums puzzled their heads continually over the meaning of the strange scene they had witnessed. Many were the theories they advanced and cast aside. One only appeared to Deirdre to be a really possible explanation. "I'll tell you what I believe," she said, "I think that man in the brown jersey is a German spy. You know, although Gerda sticks to it that she is English, we've always had our doubts. She looks German, and she speaks better German than Mademoiselle, though Mademoiselle's Swiss, and has talked two languages from babyhood. Gerda isn't an English name. She says it was taken from Gerda in 'The Snow Queen', but can one believe her? I'm called 'Deirdre' because my family's Irish, and it's an old Celtic name, but 'Gerda' is distinctly Teutonic. Then she spells Thorwaldson 'son' but in one of her books I found it written Thorwaldsen, which is most suggestive. No, mark my words, she's a German, and she's come here as a spy." "What has she to spy on?" asked Dulcie, deeply impressed. "Why, don't you see? A knowledge of this part of the coast would be simply invaluable to the Germans, if they wanted to invade us. All these narrow creeks and coves would be places to bring vessels to and land troops, and the Castle could be taken and held as a fort, and perhaps the Dower House too." "Is that why she was measuring the passage?" "It might very easily be! She'd give them a plan of the school." "Oh! Would they come and turn us out and kill us?" "One never knows what an enemy might do. This bit of shore is not at all well protected; we're a long way from a coastguard station on either side. It's just the sort of spot where a whole army could be quietly landed in a few hours, before anyone had an inkling of what was going on. There's no doubt that we ought to watch Gerda most carefully. It may mean saving our country from a terrible catastrophe." CHAPTER IX A Message