"But I couldn't find you when I looked for you," persisted Annie.
"Yes, where were you?" asked Evie again.
But to such an inconvenient question the chums prudently turned deaf ears.
Deirdre and Dulcie were determined to leave no stone unturned until they had obtained a translation of the letter which they had purloined from the bottle. They did not care to show the manuscript itself to any of the elder girls, as to do so might be to betray their secret, but by dint of asking odd sentences and words they made it out to run thus: "Very little to report. No progress at all just at present. Extreme caution necessary. Better keep clear of headland for a while, and let all plans stand over." There was neither beginning nor signature, and no date or address.
To the chums the communication had only one meaning. It must refer to a German attack upon the coast. The aeroplane had probably been prospecting for a suitable place to land troops. It was Gerda who was to supply the information needed by the foreign government as to a favourable time for executing a master-stroke.
Evidently she did not consider the hour was yet ripe. For the present England was safe, but who knew for how long?
"It's that man in the brown jersey who's engineering the mischief," said Deirdre. "When we see him sneaking about in his boat we may know there's something on foot."
"What ought we to do?" asked Dulcie doubtfully.
"Nothing can be done just now, if they're on their guard and lying low. We must be vigilant and keep a general eye over things. If anything unexpected crops up we can warn the police. But, of course, we should have to have very good grounds to go upon in that case, a perfectly circumstantial story to tell."
"We've nothing but suspicions at present."