“Boys,” he said, “we’ll go there directly after supper. I think we’d better not wait until tomorrow.”

At seven o’clock the detective and his sons presented themselves at the Tower Mansion. Hurd Applegate met them at the door.

“I’m letting you make this search,” he said as he led them toward the old tower, “but I’m convinced you won’t find anything. I’ve talked the case over with Chief Collig. He’s inclined to think that Robinson is behind it all and I’m sure he is.”

“But how about Jackley’s confession?” Mr. Hardy asked him.

“The chief says that could be a blind. Jackley did it to protect Robinson. They were working together.”

“I know it looks bad for Robinson,” Mr. Hardy admitted, “but I want to give the towers another close examination. I heard Jackley make the confession and I don’t believe he was lying.”

“Maybe. Maybe. But I’m telling you it was a hoax.”

“I’ll believe that only if I don’t find anything inside or outside either tower,” Mr. Hardy declared, his mouth set in a grim line.

“Well, come on, let’s get started,” Hurd Apple-gate said, unlocking the door leading to the old tower.

Eagerly the four set to work. They started at the top of the old tower and worked downward. Their investigation left no possibility untouched. All the walls were tapped for hollow sounds which might indicate secret hiding places. The floors were examined closely for signs of any recent disturbance to the wood. But the missing jewels and bonds were not located. Finally the group reached the ground floor again.