“I am looking for a friend,” answered Merry, likewise in French.

“Have you the sign?”

“The what?”

“The sign.”

“No; I don’t know what——”

“Then you cannot enter.”

At this moment, a voice from within cried out something in very bad French, and the man at the door suddenly stepped aside, saying:

“Enter.”

Frank hesitated a moment, and then stepped into the room. Immediately the door closed behind him with a click.

Frank stood there looking around in the dim light which came through a curtained window. He saw there were several persons in the room. At the farther end was a passage.