"Was a guard. I couldn't explain _that_.... He wanted me to marry him--to go with him without marriage--and father tried to force me.... He was trying to force me to-day.... And he died." Suddenly she clutched his arm. "Oh," she cried, "be quick! Do something!... They were warned!... I did it. I called Cantor Adolf von Arnheim. I had to do something to protect myself...." "What did he say? Was it true?" "It was true. It changed him. He forgot me.... He told father he must strike at once--to-night.... It's going to be to-night. Somehow, by some means, he's going to do some awful thing. He rushed out.... Then Philip's wife came with a note ... and when father read it he ... died. It killed him...." "To-night. Cantor is going to do something to-night. What? What else do you know?" "Let me think. It was all so terrible.... He has an aeroplane. He is going to blow up factories and channels. In an hour. He said he could do it all in an hour." "Where is Cantor? Where did he go?" "In his car. I don't know where he went--it was that way"--she pointed--"away from the city.... He said it would be easy, that there was no way to stop him." "That way? Toward the lake?" "Yes." Potter stood motionless, thinking as he had never thought before, sometimes thinking aloud. "He has Matthews's 'plane," he said. "He'll use that--to drop explosives.... He's been gone hours. He can't be caught and stopped. Once he reaches that 'plane, there's no way to stop him. Even if the city was warned, he could do as he wished.... There's no way to stop him." "But you must stop him.... If this thing is done it will be my fault--mine!... Because I didn't tell.... But now I've told.... Oh, Potter, you must do something.... I'm not a traitor.... I love my country. Don't let me be blamed for this. There's a way to prevent it--some way.... You must find it." "If we knew where the 'plane was--or the explosive stored." He stopped suddenly, and a surge of joy welled up to his eyes. "I know," he said. "I know where he must start.... That island, Hildegarde, where we fell.... That's what the island was for. They made explosive, stored explosive.... There is where he will start." "What time is it?" He looked at his watch. "Nearly six," he said. "He won't start for hours--until midnight. He'll be safest then.... Can't you get there in time?" "I don't think a motor-boat could reach that island--the ice in the lake." "_He's_ got to reach it. _He_ can reach it." "He'll have that 'plane hidden on the lake shore. He'll fly across and take on his explosives." "You have an aeroplane, too," she said, simply.