trifle too short. He carried a bag of tools and was whistling gaily some intricate tune of trills and runs as he walked along. As he turned to look out to sea, Billy saw that he had a pleasant face, cheerful, intelligent and rather sensitive. He stood for a minute, though without seeing Billy, then walked on again, swinging his bag and piping his music in the very best of spirits.
A bobolink was swinging on the branch of a bush that leaned over the wall. The gay black-and-white fellow was a new bird to Billy, so he stopped to look at it more closely. Certainly it was the bird that caught his attention not the unaccountable rustle that he heard immediately after, for that sound he might never have noticed save for the strange thing that followed.
For the rustle was repeated; then a hand rose over the wall, slipped across one of the big lichen-covered rocks and rapped upon it sharply with something metallic. The boy ahead of him stopped dead, hesitated a second, then turned slowly toward the sound. Billy could see now that there was a man there behind the wall, crouching among the bushes, some one rather small, narrow-shoul-
