"W.J. Flynn." "Why do you accuse me?" she asked. "Miss Mason, what else could one do? We arrive in time to see the explosion, the workers running out, and----" Dixie leaned forward. "The workers, are they safe?" she asked eagerly. "Most of them. Some are injured. I am glad you at least warned them." "Thank you. Now would you mind releasing my hand?" Grant looked at her in wonder. Would he ever fathom this mystery girl? Could it be possible that he had made a mistake? But in contraversion to this thought came the memory of her constant association with the Germans most active in promoting the interests of their government; her frequent appearances with Von Lertz and Madam Stephan. And what possible motive could have brought her to this scene and placed her in such a situation? "Miss Mason, I can say nothing except that a watchman told me of having seen a girl running toward the power house a moment before the explosion came. I must put you under arrest. The evidence is absolute and I can do nothing else." Dixie opened her lips, but the words were not spoken. The sharp report of a gunshot put an end to their conversation. The sound of a low cry drifted in--then silence. Grant stepped to the door and then hesitated. "I'm very sorry Miss Mason," he said reaching in his pocket, "but I'm afraid this is necessary." Something glittered in his hands and Dixie heard the metallic clink of handcuffs. "I must see what is wrong outside--and I must be assured that you will remain here until I return." Dixie held out her hands in silence. He snapped one manacle about her wrist. A strange sort of wonder possessed him that he should be thus shackling the hands of the girl who had so fascinated him in the past. She stood quietly while he attached the other cuff to the swinging door of the switchboard railing and then hurried outside. Two hundred yards away stood a watchman and at his feet lay the body of a man. As Grant reached his side the watchman reported briefly. "I saw this fellow sneaking around. When I called to him to halt he started to run, so I shot." Grant searched the body hastily with the help of his pocket flash and brought out the card of a German reservist. It was enough. Imperial Germany had scored again, and in the usual manner, with death to innocent beings and appalling destruction of property. He turned again to the power house where he had left his fair prisoner, but on the threshold he stopped in astonishment. The power house was empty! One handcuff hung on the gate of the switchboard. A rubber glove lay on the floor. The other handcuff of the pair was gone and with it Dixie Mason! CHAPTER X. THE INVASION OF CANADA