A short way down the shore was the lighthouse, long since abandoned though still picturesque. Dixie, somewhat wearied from an afternoon of skating had retreated to the shelter house. As she unlaced her skating shoes, she glanced up to see through the window a group of men passing. One of them she recognized as Harrison Grant. For a moment her heart throbbed wildly and a fear that he had come to the Inlet for the skating and that again she would be seen with Von Lertz, left her weak. But she stifled it. Her own hopes and fears and desires must not influence the work she had set her hand to. She watched with relief the group of figures as they passed on their way toward the lighthouse. A vague wonder as to their intent flitted through her mind and then was blotted out by a new interest. Madam Stephan had arrived. Dixie saw her glance over the crowd outside, single out Von Lertz and beckon to him with a gesture imperceptible to one untrained to catch the slightest gesture and attach a meaning to it. Von Lertz glided to the shore and stopped before her. They were beside the shelter house and close to the window. Dixie heard Madam Stephan's voice, quiet but ringing with suppressed excitement. "Grant has gone to raid the dynamite depot in the lighthouse." "Yes?" Von Lertz's interest was instant. "And the trap?" "Set and ready to spring." A shiver of dread passed through Dixie Mason. What was this trap they spoke of? Grant was in danger! The man whom Dixie could not forget nor put out of her mind. The man who occupied her thoughts as no man had done before. She wavered--and then straightened up determinedly. She smiled graciously at Madam Stephan, entering the shelter house. And she walked out to where Von Lertz was awaiting her still smiling, but her heart was heavy with anxiety for Harrison Grant. A man skating in long curves glided past and then with a sudden turn faced her. He glanced at her closely as he skated slowly backward. Dixie had seen him several times during the afternoon. She had noticed him eyeing Von Papen and Boy-Ed. A faint hope came to her. Could it be that he was a "forward shadow?"--the man who takes the risks of the Secret Service to aid some other man to gain evidence? She caught his eye, and winked quickly, her eyelids making the dots and dashes of the Morse code. "Secret Service?" she signalled. The man nodded. Dixie's heart bounded with hope. She signalled again. "Grant--danger--lighthouse!" She turned to Von Lertz. Looking back she saw the Secret Service man making for the shelter house. The two men whom Harrison Grant and his operatives found in the lighthouse submitted to arrest with unusual alacrity. The ease with which they were taken puzzled Grant for a moment but it was forgotten in the interest awakened by the place they had raided. Grant ordered the men to drive to headquarters with the captured spies, deciding to make further investigations himself.