is face."

"Who carried him out?"

"Why, the men from the hospital who were sent for."

"What floor?" demanded Ned, a thought he did not care to put into words
coming to his mind.

"Third floor," replied Peter. "I stood out there, looking around, when the
chair was brought down on the freight elevator."

Greatly to the amazement of the boys Ned darted away. In a minute he stood
before the clerk's desk.

"Will you have a boy show me to Lieutenant Gordon's room?" he asked.

"Certainly," was the reply, "but you won't find him in. There have been
repeated inquiries, for him this afternoon."

"Has any one been to his room?" asked Ned.

"Yes, but it is locked and the key is not here. I was up on that floor
about five o'clock, when the hospital people took a man out of the room
next to his, and his door was locked then."

Ned stood for a moment in deep thought, hesitating, wondering if the clerk
was a man to be trusted in a great emergency.

"You look to me like a dependable man," he finally said to the clerk,
"anyway, I've got to take you into my confidence. Will you take duplicate
keys to the lieutenant's room and the room next to it and come with me?"

"Of course, if it is anything important," replied the clerk, "but you'll
have to give some good reason before I can admit you to either room."

"Step in here," Ned said, motioning toward a little check room at the end
of the counter. "You saw the sick man carried out?" he asked, as the clerk
wonderingly stepped into the designated room.

"Yes, I saw him taken out. He was a stranger--took the room about noon
through a friend. I did not see him at all, that is, until he was carried
out, and then I did not see his face."

"You are sure it was not Lieutenant Gordon who was carried out?" asked
Ned.

"Why, why, he wasn't sick. He said nothing to me of being ill."

"But he has enemies on the Isthmus," Ned went on, "and is now at work on a
very delicate and dangerous job for the government. Suppose--"

The clerk waited to hear no more. He seized the keys asked for and bounded
toward the elevator, taking Ned with him. When they entered the
lieutenant's room they found it in great disorder. There were many signs
of a desperate struggle. On the floor was a three-cornered slip of paper
which had evidently, judging from the quality and thickness, been torn
from a drawing roll. The scrap showed only two irregular lines, but Ned
recognized them.

Lieutenant Gordon had