Sally was quite overcome with amazement at this elaborate system of reasoning it out. “You certainly are a wonder!” she exclaimed. “I never would have thought of it in the world.”

“Why, it was simple,” declared Doris, “for just as soon as I’d hit upon that first idea, the rest all followed like clockwork. But now, if all this is right, and the treasure lies somewhere under the vacant square, our business is to find it.”

Suddenly an awful thought occurred to Sally. “But how are you going to know which corner that square is in? It might be any of the four, mightn’t it?”

For a moment Doris was stumped. How, indeed, were they going to tell? Then one solution dawned on her. “Wouldn’t they have been most likely to consider the square of the floor as it faces you, coming in at the door, to be the way that corresponds to the plan on the paper? In that case, the extreme right-hand corner from the door, for the space of twenty-one inches, is the spot.”

It certainly seemed the most logical conclusion. They rushed over to the spot and examined it, robbing Genevieve of her candle in order to have the most light on the dark corner. It exhibited, however, no signs of anything the least unusual about it. The rough planks of the flooring joined quite closely to those of the wall, and there was no evidence of its having ever been used as a place of concealment. At this discouraging revelation, their faces fell.

“Let’s examine the other corners,” suggested Doris. “Perhaps we’re not right about this being the one.”

The others, however, revealed no difference in their appearance, and the girls restored her candle to Genevieve at the table, and stood gazing at each other in disconcerted silence.

“But, after all,” suggested Doris shortly, “would you expect to see any real sign of the boards being movable or having been moved at some time? That would only give their secret away, when you come to think of it. No, if there is some way of opening one of those corners, it’s pretty carefully concealed, and I don’t see anything for it but for us to bring some tools up here,—a hammer and saw and chisel, perhaps,—and go to work prying those boards up.” The plan appealed to Sally.

“I’ll get some of Dad’s,” she declared. “He’s got a lot of tools in the boathouse, and he’d never miss a few of the older ones. We’ll bring them up tomorrow and begin. And I think your first idea about the corner was the best. We’ll start over there.”

“I’s cold,” Genevieve began to whimper, at this point. “I don’t like it in here. I want to go out.”