“I can’t imagine,” Dories replied. “If only Gibralter were here with his punt, we might be able to find out.” Then she exclaimed merrily, “Nann, there is another mystery added to the twenty and nine that we already have.”

“Not quite that many,” the other maid replied, giving one last long look in the direction they believed the plane had descended or fallen. “I’m inclined to think,” she ventured, “that there is a bay or something beyond the swamp. O, well, let’s go back to our task. It’s lunch time, if nothing else.”

They decided, as the day was unusually warm for that time of the year, to eat a cold lunch, and, as their aunt did not wish anything then, the girls decided to walk along the beach in the opposite direction and see if they could find the cove where Gib kept his punt in hiding. But, just as they reached the spot where the road from town ended at the beach, they heard a merry hallooing, and, turning, they beheld Gibralter Strait riding the white horse that was usually hitched to the coach.

“Oh, good, good!” was Dories’ delighted exclamation. “Now perhaps we will find out about the plane. Of course the people in town saw it and Gib may know——” She stopped talking to stare at the approaching steed and rider in wide-eyed amazement. “How queer!” she ejaculated. “Nann, am I seeing double? I’m sure that I see four legs and Gib certainly has only two.”

There were undeniably four long, slim legs, two on either side of the big white horse, but the mystery was quickly explained by the appearance, over Gib’s shoulder, of a head belonging to another boy.

“Nann Sibbett!” Dories whirled, the light of inspiration in her eyes, “I do believe that other boy is Dick Burton, of whom Gib has so often spoken.”

And Dories was right. Gib waved his cap, then leaped to the sand, closely followed by the newcomer. One glance at the young stranger assured the girls that he was a city lad. His merry brown eyes twinkled when Gibralter introduced him merely as the “kid that was crazy to find a way into the old ruin.”

The city boy took off his cap in a manner most polite, adding, “By name, Richard Ralston Burton, but I’m usually called Dick.”

Nann, realizing that Gib hadn’t the remotest idea how to introduce his friend to them, then told the lad their names, adding, “Oh, Gib, you just can’t guess how glad we are that you have come at last. The mysteries are heaping up so high and fast that we simply must solve a few of them.”

But it was quite evident that the boys were equally excited about the airplane, which they, too, had seen as they were riding on the white horse along the road in the swamps. “I say,” Gib began at once, “did yo’uns see where that airplane fellow dove to? D’you ’spose he’s smashed all to smithereens on the rocks over yonder?”