Not once during all this time, had there been the least reference to the mysterious hint of Sally's during the earlier afternoon. But this was not at all because Doris had forgotten it. She was, to tell the truth, even more curious about it than ever. Her vivid imagination had been busy with it ever since, weaving all sorts of strange and fantastic fancies about the suggestion. Did the river have a mystery? What could its nature be, and how had Sally discovered it? Did any one else know? The deepening shadows on the farther shore added the last touch to her busy speculations. They suggested possibilities of every hue and kind. But not for worlds would she have had Sally guess how ardently she longed for its revelation. Sally should tell her in good time, or not at all, if she were so inclined: never because she (Doris) had _asked_ to be admitted to this precious secret. They beached the canoe, still talking busily about the morrow's plans, and together hauled it up in the sea-grass and turned it bottom upward. And then Sally prepared to take her departure. But after she had said good-bye, she still lingered uncertainly, as if she had something else on her mind. It was only when she had turned to walk away across the beach, that she suddenly wheeled and ran up to Doris once more. "I--I want to tell you something," she hesitated. "I--perhaps--sometime I'll tell you more, but--the _secret_--Genevieve's and mine--is up on Slipper Point!" And before Doris could reply, she was gone, racing away along the darkening sand. CHAPTER III SALLY CAPITULATES It was the beginning of a close friendship. For more than a week thereafter, the girls were constantly together. They met every morning by appointment at the hotel dock, where Sally always rowed up in "45," and Genevieve never failed to be the third member of the party. The canoe was quite neglected, except occasionally, in the evening, when Doris and Sally alone paddled about in her for a short time before sunset, or just after. Sally introduced Doris to every spot on the river, every shady bay and inlet or creek that was of the slightest interest. They explored the deserted mill, gathered immense quantities of water-lilies in Cranberry Creek, penetrated for several miles up the windings of the larger creek that was the source of the river, camped and picnicked for the day on the island, and paddled barefooted all one afternoon in the rippling water across its golden bar.