Blake stood up slowly. "Supposing Wade isn't the chief," he asked. "What then?" "They'll kill us all, just as they already plan to," O'Toole groaned. "We might as well take a flying chance." Blake shook his head. "I've got a better idea," he said. "Then spill it. We haven't much time." "To begin with," Blake said. "If Wade was in this he'd have shown up here long ago. The paper said he couldn't be located. I'd recognize my twin even in one of these outfits." O'Toole protested. "Then who is the chief? He's here somewhere and Slater sure didn't intend to take orders from Harror." "He must be on the train," Blake answered. "Now you're crazy," O'Toole answered savagely. "The people on Mono 6 have been locked up for hours. If the leader of the Silver Masks was among them he'd have taken charge hours ago." "Unless," Blake said thoughtfully, "he didn't want any of us to _know_ he was the leader." O'Toole pulled the mask down over his eyes. "Let's get out of here," he said. "You've got something up your sleeve and I'll play the cards the way you want them." "One more thing," Blake told him. "These men had to have a track to get Mono 6 into this cave. When it goes out again we'll be on the same track, but it will end in a canyon or deep lake." "Go on." "Well! We've got to get started on that trip. After we are out you and I will have to take our chances of stopping the mono." "And I thought Grudge Harror was a tough baby," O'Toole grinned. * * * * * "It isn't a matter of being tough," Blake said. "Can you handle the engine room alone?" "Handled it for years," O'Toole said coolly. "But I'd like to know where that track ends." "You will." Blake went toward the door. He gripped O'Toole's shoulder. "You're a good Irishman, O'Toole. Now go out of here and straight to the cab. I don't think they'll dare send one of the other men. If the controls are tied into place, leave them alone. When I signal, set all motors going full speed. Sit tight and keep her flying." "And the end of the track?" O'Toole asked. "If I don't get shot in the back before I'm half way across the cave, how do I know when to stop?" Blake chuckled dryly. "Perhaps you won't," he admitted. "But I'll be in the rear lounge with every male passenger within my sight. One of them is bound to break down when he knows he's at the end of the trail." "So?" "I'll jerk the emergency cord," Blake said. "Set your brakes the minute you hear it. O'Toole, it's a long chance but we've got to take it." "One more thing," O'Toole asked. "Blake, who in hell is the leader of the Silver Masks?" Blake hesitated, his face darkening. He opened the door and pushed O'Toole out gently. "If I'm not mistaken," he whispered evenly, "Walter Ferrell knows more about this than he's telling." * * * * *