Then one day, quite unexpectedly, something happened. It was a wild, windy March morning, and the girls were taking a hasty run on the warren between morning school and dinner, to "blow away cobwebs" and give them an appetite. There was not time to go far, but they dispersed in all directions, trying which could make the biggest distance record available. Gerda had started with Annie Pridwell and Betty Scott, but under pretence of beating their speed she had got considerably ahead and left them panting in the rear. "Where's Gerda?" asked Deirdre, who, with Dulcie and Evie Bennett, had followed the first "threesome". "We simply can't keep up with her! She walked as if she had seven-leagued boots. She's gone over the hill there. I'm going to wait till she comes back." "There's no sense in flying like the wandering Jew!" protested Betty. "I hope she won't be long, because I don't want to walk back as fast as I came." "Dulcie and I'll go after her," said Deirdre promptly. "We don't mind running. You two can be toddling along with Evie as leisurely as you like." It only meant a change of "threesomes", so the girls agreed readily and departed at once, leaving the chums to act escort to the truant. "She's done it on purpose," gasped Dulcie as soon as they were alone. "Of course. It's a perfectly transparent dodge. Now we must do Secret Service work again and not let her see she's being followed." The chums really congratulated themselves that they were getting on in the matter of scouting, they availed themselves so cleverly of the cover of rocks and bushes and proceeded with such admirable caution and care. Their efforts were successful, for after a few minutes of skilful stalking they caught sight of their quarry. Gerda was climbing down the cliff side, fully a hundred feet below them, and had nearly reached the level of the beach. She descended quickly, almost recklessly, scrambling anyhow over rocks and through brambles, and splashing through a boggy piece where a trickle of water had formed a pool. Arrived on the shingle, she went straight to a hole among the rocks, searched in the seaweed, and produced a bottle. Taking a piece of paper from her pocket, she folded it into a long narrow slip and put it inside, replacing the cork tightly. Then she ran towards the crag at the mouth of the cove, and climbing up higher than was compatible with safety she hurled the bottle as far as she could throw it into the sea. She stood looking for a moment or two as it bobbed about on the surface of the water, then, turning round, began to scramble back with more haste than care. "We've seen enough! Come quick before she spies us!" whispered Deirdre, dragging Dulcie away. "We mustn't let her know we were anywhere near. Let us run and be a long way off before she gets to the top of the cliff and sees us."