Tom Dodd was one of the last off. He had two suitcases under one arm, and he was supporting Marks with the other. Rick and Scotty ran to help. Was the scientist ill? Scotty took the suitcases while Rick grabbed Marks' other arm. The scientist shook him off. "I'm perfectly all right," he said irritably. "Confound it! Rouse a man at the crack of dawn and expect him to respond like a ballet dancer to a cue. Nonsense!" Marks' appearance belied his words. His face was drawn and pale, and it was obvious that his coordination wasn't very good. Tom Dodd was plainly worried. "Let go of me," Marks demanded. He drew himself up and glared at the boys. "Which way is the car, please?" "Straight ahead." Rick glanced at Dodd. Marks stalked off, but his step was too careful to be convincing. He just wasn't normal. "He wasn't like this when we got on the train," Dodd said in a low voice. "Let's get going. I'm anxious to get him to Spindrift." In the parking lot, Rick ran to open the trunk so Scotty could stow the bags. Then he beckoned to Marks, who was staring straight ahead, his eyes glassy. "This is the car, sir." Marks started for the open door. But instead of bending down to get in, he walked straight ahead, rigid as a robot, and his face slammed into the edge of the low turret top. Dodd caught him as he fell. Rick jumped to the scientist's side, afraid he had been knocked out, and afraid, too, that something even more serious was wrong. Marks was not unconscious, but his stare was fixed. "Are you all right, sir?" the boy asked anxiously. The reply was unintelligible. Scotty bent over the scientist, too. "Are you all right, sir?" he repeated urgently. Marks' fixed stare never wavered. A spate of words poured from him, but they made no sense. Now and then a single word emerged clearly. Once it was "July," then "soup kettle" and "Planck's constant." "Just like the others," Tom Dodd said helplessly. Rick listened with horror. He had no doubt, no doubt at all. Steve had described it accurately, and here it was. Marks was a victim of the identical ailment that had stricken the other team members! CHAPTER IX Dagger of the Mind Tom Dodd took command and gave orders crisply. "Help get him into the car. Here, into the back seat." The agent got in after the scientist while the boys got into the front. "Scotty, start driving. We have to shake off any tail that picks us up. Try to find a stretch where there isn't much traffic." Scotty swung the sedan into the traffic stream while Rick joined Tom Dodd in watching behind them. A few minutes later Scotty slipped into an alley and stepped on the gas. At the end of the alley he turned the wrong way down a one-way street, found another alley, and slipped into it. He emerged under a railroad trestle and moved into the stream of traffic once more. Watching carefully, he moved with the traffic until he saw an opportunity to cross a main thoroughfare as the light changed from yellow to red.