The Sundial by Fred M. White

It was a cruel dilemma for the girl, but her courage and intelligence returned and she began to see how to act. Nothing was to be gained by rousing Mrs. Rent. Possibly before she woke Arnold would be found. But where to look for him, and which way to turn Ethel did not know. Perhaps the best thing would be to go at once to Rent's workshop on the shore. No doubt what was troubling him was in some way connected with his researches and it was an obvious inference that he had gone in that direction. Ethel slipped into a wrap and without waiting to put on a hat walked into the darkness.

She knew which way to go, because the workshop had already been pointed out to her. She did not mind the dark and lonely journey. She flew swiftly over the broken ground and gave a gasp of relief when she saw a light in one of the offices. Her search seemed to be finished almost before it had begun. Taking her courage in both hands, she opened the door of the office and walked in.