“No, it seems to be empty,” said Mr. Blake, leaning over and lifting up the queer box, which was made of wood. “I guess this wasn’t taken from the post-office,” he said. “The burglars may have stolen it somewhere else. We’ll leave that in their boat. Maybe they stole the boat, too. Tow it to shore, Mr. Martin—that and the box and we’ll keep on after the burglars.”

So while Mr. Blake and Mr. Addison, in their motor boat, puffed on toward the place where the two men had landed in their rowboat, Daddy Martin and Uncle Ben fastened a rope from the half sunken craft to their Gull. Then they began slowly towing it back across Silver Lake. But not before Daddy Martin had lifted out the queer, wooden box.

So much had happened, and there was so much to talk about, that no one paid much attention to this box. It was not until the Curlytops and the others had landed at the Sunnyside dock that any one thought of the box. The motor boat from which the burglars had jumped was made fast to the pier, in shallow water, so that if it sunk completely it could easily be got up again. But it seemed to want to sink only half way.

“My, you’ve had a lot of adventures!” exclaimed Mother Martin, when she heard all that had happened. “I wonder if they got the robbers?”

“No, they got away,” answered Uncle Ben, who had gone out to a telephone to inquire. “The robbers got away, but we got back the money and stamps they took.”

“And the queer box, too,” added Ted.

“What queer box is that?” asked Mrs. Martin.

“Why, one we found in the wrecked motor boat,” her husband answered. “Here it is. I haven’t had time to look at it.”

As he spoke he handed the box to his wife. It was square, and made of some light and finely polished wood.

“Why!” exclaimed Mrs. Martin, as she looked at the queer box, “do you know what I think this is?”