“You think that is what has happened?” asked Douglas, elevating his eyebrows. “That sounds rather wild, don’t you think?”

“Perhaps it does,” answered Nick. “But I’ve been on the trail of a wild man since I came to San Juan, and I fancy I can detect the fine Italian hand of that person in this whole affair.”

Captain Douglas knew the reputation of Nick Carter as a detective who did not make mistakes, and he had the highest respect for his ability and acumen. He did not press his objection.

At the worst, he would have Carter to share the responsibility.

“All right, Mr. Carter!” he said. “Let her go!”

Nick Carter, Chick, Patsy, and Clayton put their shoulders against the door, and, at a word from Nick, the four pushed with all their might.

There was a crash, but the door did not break down. Only a splintering of wood told that it had been weakened by the assault.

“Stop!” shouted Captain Douglas. “I’m afraid to go on with this. It is liable to put us all in jail. You can’t fool with the United States government. This is a government building, and I don’t propose to——”

Nick Carter took no heed of this protest. He had made up his mind to find out what was in this room, at any cost. He had come so near the actual truth in his surmise, that he would not have drawn back now, no matter who might have objected.

“Again, boys!” he shouted.