“Did you think that perhaps we were pirates too?” laughed Sue.

This “unfortunate remark,” as Isabel called it later, required explanation, and the girls were only too ready to tell all their suspicions about the Cove, and its unknown Robinson Crusoe. He listened to them with the keenest amusement, his dark eyes twinkling under their “pent-house lids,” as Ruth called the bushy gray eyebrows.

“So you considered me a pirate or a smuggler, did you?” He laughed richly over the idea, but Polly shook her head.

“Not exactly. We thought you might be. We almost hoped you might be, so we could find chests of gold in that cave. You see, nobody around here knows anything about you, or where you came from, or when you came.”

“I came up from the South in a motor boat along the shore,” he replied promptly, almost happily. “And a rousing good time I had too.”

“But where were you all the time we were on the island, and Crullers nearly was drowned when she got in the way of the Portland?” Polly leaned forward, her chin on her hand, as she always did when she was perplexed.

“I had gone away from the island for the day,” he explained. “Up to Pautipaug Beach. It is about twelve miles along the coast towards Bar Harbor.”

“Well,” sighed Polly, “we’ve called you the Mystery, and it certainly suits you, for nobody knows even your name.”

“That’s just what I wanted,” he answered, comfortably. “That’s why I came here.” He leaned back in the most comfortable chair the club boasted, and piled cushions behind him, while Ted slipped away to tell Aunty Welcome of the guest of honor. “I’ve rented Smugglers’ Cove for the summer for research, yes, that’s a good word, very explanatory and truthful, for research. And—well, that’s all there is to it.”

There was a dead silence, while each of the girls regarded the mystery from her own point of view. Nobody questions a guest, not around Queen’s Landing, Virginia, not even when he is shrouded in mystery, so they gave it up. But Polly had a brilliant strategic plan occur to her. She would introduce all of the girls, gracefully, easily. Then he would have to introduce himself to them in return. It was simple.