“Maybe Emma Tash has been here without us knowing it and has taken Melissa away,” explained Terry. “That detective woman was smart. She may have come here, met George Clayton and Melissa, and have prevailed on him to let her take the girl. That would account for their being gone now.”

For a moment they were inclined to accept this theory. Then Arden, as usual putting her finger on the critical point, said:

“It wouldn’t account, though, for the barking of Tania.”

For the first time they all realized that the dog was barking with an unusual note in the tone and that she kept it up almost continuously. Up to this moment they had been so engrossed with approaching the shack without inciting George Clayton to the point of desperate resistance that they had not paid much attention to Tania.

Now they noticed that the dog was running about the shack in a most excited manner, scarcely ceasing her growls and barks. And, now that their attention was fixed on her, they saw that she stopped at a certain cellar window and barked there with unusual vigor.

“The barking of Tania,” murmured Sim. “No, the taking away of Melissa by the detective woman, with her father’s consent, and his desertion of his home, would not account for the barking of Tania. Arden, I think we are going to make a discovery—a big discovery.”

“What do you mean?” faltered Terry. “Do you think Dimitri——” She could not finish. She dared not finish. But the others knew what she had in mind.

“Now you speak of it,” said the chief, “that dog is making quite a row. Barking dogs, you know, catch no cats. But we’ll see what’s up.”

“You think, don’t you, Sim,” said Arden, “that there is something in the cellar?”

“I can’t help but think that, from the way Tania acts. Look at her now, barking into the window.”