“I went in and sat waiting for a few minutes. But my restlessness made me get up again, to walk about a little. As I passed out I saw some marks on the sand, close under the front of the boathouse. I stooped down to examine them, and discovered a word written in large letters on the sand. The word was⁠—

Look

.”

“And you scraped away the sand, and dug a hollow place in it?”

“How do you know that, Marian?”