"I know there isn't," responded Dixie with a twisted smile, "but it is almost unbelievable to me that at last we have done something without Harrison Grant knowing of it. I feel apprehensive for some reason. Are you sure there is no one in the hallway?"
"Why this is most unlike you, Miss Mason," responded Von Lertz. "But come see for yourself and relieve your worry."
He threw the door open and gave Dixie's arm a little re-assuring squeeze and she gazed up and down the long empty corridors.
"I believe I am making myself nervous with this old string," she said, ruefully casting it from her onto the floor.
"At least you know there is no one spying," said the German as he turned back into the room.
His voice would have lost the confidence it expressed as he continued to pour assuring words into her ears, if he could have known of a happening in the corridor. Scarcely had he drawn the door shut, when the door of the room across the corridor opened and a bellboy, who a moment before had been crouching inside with his eye at the keyhole, emerged. Stooping quickly to pick up the string which Dixie had thrown away he sped noiselessly down the corridor to the elevators.
But Von Lertz did not know, and continued to enlarge upon the efficacy of the precautions which had been taken, and how impossible it was for the Secret Service to have learned anything of the present plot. As he was talking a knock came on the door and a bellboy, the same one who had taken Dixie's piece of string from the floor of the corridor, put his head in:
"Did you ring, sir?" he asked, "No, sir? I am sorry."
The door was closed but a message had been delivered. To Dixie Mason the appearance of the bellboy at the door meant that her bit of string had reached Grant and had been understood. On the string she had tied knots spaced to the dots and dashes of the Morse code spelling out the following message:
"Lock fourteen. Ten o'clock. Watch alley."