"To give him measles? How kind! But I'd travel in a cattle-truck to get home. Only one week of the holidays left! I mean to get the most amazing amount into the time, I assure you." Deirdre and Dulcie were travelling together to Wexminster, where their ways parted, and Gerda was to go on to Hunstan Junction, where she would be met by a relative. If she was pleased at the prospect, she did not betray much excitement, nor did she vouchsafe any details of what was in store for her. The chums were too busy with their own plans to concern themselves with hers, and jumped out of the train at Wexminster in such a hurry that they almost forgot to bid her good-bye. Rather conscience-stricken, Dulcie remembered just in time, and turned back to the carriage window. "Good-bye! I hope you'll have as jolly holidays as mine," she called. "Thank you!" said Gerda, waving her hand, with a wan little smile, as the train began to move. And for the first time since they had known one another, it struck Dulcie that there was something infinitely sad and pathetic about her mysterious school-fellow. Could she really be a spy? The chums had discussed the question again and again. Her German associations, her intense reserve, and, above all, her incriminating meetings on the shore, seemed highly suspicious. What was the secret that she so persistently concealed? And what the explanation of the letter she had placed in the bottle? For the present the riddle must remain unanswered. Both they and she had turned their backs on Pontperran for one brief week, and during that time neither suspicions nor speculations must disturb the full bliss of their belated holiday. Deirdre and Dulcie made up for the shortness of the vacation by the thorough enjoyment of each precious day, and when they returned to the Dower House had enough material for conversation to last them a month or more. Even Gerda appeared cheered by the change. Though she did not offer any details of her doings, she admitted she had enjoyed herself in London. She looked brighter, and was more ready than formerly to join in the life of the school and take some part in all that was going on. The chums watched her closely, but found her conduct perfectly regular and orthodox. She indulged in no more surreptitious expeditions to the shore, and did not attempt, when on the warren, to separate herself from the others. Since the day they had been marooned on the island, Deirdre and Dulcie had not seen the brown-jerseyed stranger again. They concluded that he must have left the neighbourhood, and have suspended his evil designs till a more favourable season.