The dog leaped alongside as the old man went down the steep, wet stairs that led to the wharf, near which a dory was floating.

The girl stood in the open door, and with shaded eyes watched the scudding sailboat until, as was his custom, her grand-dad turned to wave to her as he passed the first buoy.

There were many buoys, painted in varying bright colors, that the skipper of each incoming fishing smack might have no trouble in locating his own particular mooring place. On a moonlighted night, when the sailing boats were all in, it was indeed a pretty sight to see the flotilla, some newly painted and others weather-stained, bobbing on the choppy waters of the bay.

Windy Island, though only a quarter of a mile wide, was nearly a mile long, and protected one of the snuggest little harbors to be found along that wild, rugged coast.

As soon as the kitchen was shipshape, Muriel raced toward the outer edge of the cliff, calling “Yo-o, come on, Shagsie, ol’ dog. We’ll cruise back to the cave.”

But Rilla did not enter her Treasure Cave again that day, for in another moment, and quite unexpectedly, she was launched upon her very first real adventure.

CHAPTER III.
A FIRST ADVENTURE.

Muriel did not have to call a second time to her shaggy friend, for up the steep, wet steps from the wharf the dog leaped and lifted intelligent, inquiring eyes. “Don’ let’s go to the cave fust off, Shagsie.” The girl always talked to her four-footed companion as though she were sure that he could understand. “Let’s go to that pebbly beach war yo’ found suthin’ yesterday an’ lost it. Mabbe it got washed up shore agin, whatever ’twas. Mabbe now! What say, ol’ Shags?”

Knowing that a reply was expected when his mistress stooped and stroked his head, the dog yapped eagerly, then raced alongside of the barefooted girl, who followed an infrequently used trail which ambled along toward the north end of the island, where the beach was wildest.

The shore, however, could not be seen until one was nearly upon it. When it came within the vision of the girl she stood still so suddenly that Shags, having kept on, was several lengths ahead before he was conscious that he was alone.