"Now, girls, you are forgetting yourselves," said Miss Ladd warningly. "Remember that the first requisite of skill in your work here is caution. The reason I didn't say anything to you about what I saw is that I was afraid some of you might betray your interest in the fact that we were being watched. I saw two girls half hidden in a clump of bushes up near the top of the hill. I am sure they were watching us. They were there at least half an hour."