“What do you find here?” asked Frank, following him into the closet and through into the bathroom.

“The third man might have been hiding in here,” Ned replied. “When were you in this bathroom last?” he added, looking carefully about the place.

“Not since early in the afternoon.”

“The suite was unoccupied all the afternoon?”

“Yes; I am rarely here in the afternoon.”

“What time did you come up here after dinner?”

“It was probably eight o’clock, for Dad was telling a rather interesting story at table, and we sat a long time. Mother is away on a visit to the Pacific coast.”

“And your father went to his room then?”

“Yes; he said he had some work to do.”

“His room, also, was unoccupied all the afternoon?”

“Yes; it must have been.”

“Who is usually about the lower part of the house during the afternoon?”

“No one when mother is away.”

“Do you know whether anything was taken from your father’s room?”

“Why, I haven’t heard that feature of the case discussed. We can soon find out by asking him.”

“Gee!” cried Jimmie. “What would they want to go an’ dope him for if there wasn’t something in his room they wanted?”

“That is a very pertinent question,” Lieutenant Gordon remarked. “It certainly seems that the thieves came here for something besides the emerald necklace.”

“Meaning the papers?” asked Ned, with a laugh.

“Meaning the papers, of course,” was the reply. “I am still of the opinion that the theft of the necklace was only incidental.”

“It begins to look that way to me,” observed Frank. “As Jimmie says, what would they attack father for unless they wanted to search his room?”

“You know about the papers?” asked the lieutenant.

“Yes, indeed. They constituted the subject of the interesting story Dad was telling me at table to-night.”

“Did he tell you what they contained?” asked Ned.

“He did not. He told me only what they dealt with.”

“He believes there is a plot against the completion of the Panama canal?”

“Oh, yes; he is quite certain of it.”

“Did he mention the parties he suspected?”

“He refused to do so. I can’t understand why he should refuse. Can you?”

“I think I can appreciate his position,” replied Ned.

“Great Scott!” cried Frank. “Do you think the agents of the men we are to grapple with in the Canal Zone have been in this house to-night? If so, it looks like they were looking us up, instead of our being after them.”

“Where is this man Pedro?” asked Ned, not answering the question.

“He was in the study when I left, a few moments ago.”

“Then we will go down there. I want to ask him a few questions.”

At the foot of the staircase, they heard the telephone ringing, and Frank went into the closet. When he came out again he seemed excited and unnerved.

“I guess there’s something more than the necklace at stake to-night,” he said, “for Dad’s rooms in the newspaper building have been ransacked. I guess we won’t have to go down to Gatun to lock horns with the men who are in this plot against Uncle Sam. If the Gatun dam was in New York, they might have blown it up to-night, for all that has been done to thwart them.”

“Well, we’ve just got to work on the case,” grinned Jimmie.