The driver, who was a wiry, sallow-faced man with pitted skin and dark eyes, wore a black cap to cover his almost totally bald head.
     "Attention," he called in a rasping, somewhat high voice, as he came through the restaurant door. "Attention, I'm afraid there will be a little delay. The bus has broken down. They will have to send a new part out from Munich."
     "How long will that take?" Professor Bagley asked.
     "Not long," the driver said. "You can find accommodations at the hotel next door for the night. The part should be here by noon tomorrow."
     "Tomorrow!" the professor cried. "Oh, see here, that will throw our schedule off completely. What's wrong with the bus? Several of our students are excellent mechanics. Why not let them take a look?"
     "No!" the driver shouted, his face suddenly burning with anger. "They cannot fix it. I myself am an expert mechanic. I know what I'm talking about. These are mere boys. They know nothing."
     "Do you suppose this would help you repair your bus, Mr. Expert Mechanic?"
     The bus driver whirled to see Nancy standing in the doorway holding an automobile part at eye level. The driver turned pale.
     "I don't need a woman's help," he blustered. "The part will be here in the morning."
     "What is it exactly?" Professor Bagley said, adjusting his spectacles and peering hard at the object in Nancy's hand.
     "It’s a distributor cap, sir," Nancy told him. "If you remove it from an engine, there's no way for the electricity to flow to the spark plugs. I just saw our driver take this distributor cap off the engine and throw it into the bushes."
     "In that case, we'd better call the police," Professor Bagley said coldly, advancing toward the culprit. The driver, cornered, took a step toward the door, but Ned, Dave, and Burt were already blocking it. Before anyone could stop him, the man turned and dived through a window!
     He hit the ground, rolled, and came up running.
     "After him! Get him!" the professor cried as the students burst out the door to chase the man. Ned had almost caught up and was ready to make a flying tackle when he heard warning shouts and screams behind him. He turned just in time to see an ominous black sedan bearing down on him in almost complete silence.
     The young collegian had stopped for only a fraction of a second, but the danger of his situation made everything suddenly appear to move in slow motion. He felt his leg muscles contract and expand as his body leaned and he threw his arms up and out in a spread-eagle dive, feeling the wind rush beneath him. The car barely missed him, and Ned crashed into a ditch where he rolled over twice before coming to a sitting position.
     He was just in time to see the car slow down, the door on the passenger side swing open, and the bus driver leap in. The door closed silently and the phantom car disappeared swiftly over the horizon of a hill.
     "Boy, oh, boy!" Dave yelled as he led the charge of young people forward to see if their friend was all right. "I thought he was going to hit you for sure, Ned."
     Ned got up, limping and massaging his left knee. "Twice in one day on that leg." He groaned. "Once in the airport and now here." He flexed his leg and then grinned. "It's okay. But did you hear that car?"
     "No," Nancy said. "I couldn't hear anything."
     "That's what I mean. No sound! The driver had to be going at least sixty when he passed me. Then he stopped about twenty feet away. And when that little rat-faced guy jumped in, that zoomed off without so much as a whisper."
     "Well, it's custom-made," Nancy commented. "It looked like a Daimler, a Mercedes, and half a dozen other cars combined."
     "Anybody see the driver?" Bess asked.
     "I did," Nancy said. "And guess who? The porter who tried to steal the luggage. I'll never forget that face."
     As soon as she could, Nancy cornered the professor alone. "Dr. Bagley, do you know something that maybe I should know? I realize we're all your students right now, but I'm also a pretty good detective. How about it? What's going on?"
     The professor studied his pipe, which had gone out as usual, and then he motioned her to come with him. "Let's go get some lunch, and I'll try to explain."
     But once they were seated at the neat red-and-white checkered table in the rear, Dr. Bagley spun the conversation out slowly. Nancy waited, conquering her inner impatience while the professor ordered them both a light lunch and exchanged small talk with the waitress dressed Bavarian peasant-style.
     When the waitress finally left, Professor Bagley cleared his throat, hunched his shoulders, and peered down at Nancy with his friendly, educated-owl expression. "Nancy, what I'm going to tell you must be kept in the strictest confidence. The safety of ten helpless children depends on your silence."
     The girl detective nodded, feeling the hairs along the back of her neck prickle.
     "I'm very much afraid," the man began with a sigh, "that in trying to do a good turn for a band of unfortunate little orphans I have placed my entire student tour in the most awful danger."
     Nancy waited to hear more but the professor lapsed into silence, thinking. The tension built quickly inside her, forcing her to speak. "What kind of danger, sir?"
     The professor brought both hands down on the table in an expression of frustration. "That's the maddening part of it," he snorted. "I don't know! I don't know how desperate these people may be or what they may do. Right now they seem to be doing nothing more than delaying us. But as the zero hour draws nearer, who knows to what extremes of violence they may be driven?"
     Once again the man became quiet, causing Nancy to burst with curiosity. "Professor Bagley," she said, gathering courage, "do you realize you've told me absolutely nothing except that you have to help ten children and that our tour may be in danger?" Her eyes twinkled at him. "Believe it or not, I guessed that last part."
     The tour leader stared at her, then broke into his characteristic soft chuckle. He shook his head. "The absentminded professor," he said. He ran his hand through his unruly hair. "You know, Nancy, you have the most charming way of telling a boring old teacher that he's being—well, boring!"
     Nancy started to protest. "Oh, no, sir. I didn't mean that."
     But Dr. Bagley waved his hand and smiled. "No, no, no. I understand. Of course, you didn't. All right, let me get to the point. I’ll start at the beginning."
     He cleared his throat. "I trust that you will keep what I'm about to tell you completely confidential."
     "Of course," Nancy assured him.
     "From time to time, I work for our intelligence unit."
     "You mean you're a secret agent for the United States?" the young detective asked, prompting a nod from the professor.
     "About a month ago, I was approached to help a refugee repatriation group. These people take care of anyone needing their assistance to leave any of the oppressed countries of Eastern Europe and come to the West, that is, to Western Europe and America.
     "They asked me to use this tour as a cover to help them bring across the Austrian border ten orphaned children whose closest relatives have already defected. Most of them are living in France, England, or America."
     "The children range in age from six to thirteen. Unfortunately, the communist government of their homeland refuses to see this as a nonpolitical undertaking to reunite orphans with their families. Instead, they say that the government will take care of the children, and any attempt to bring the orphans out of Eastern Europe will be viewed as kidnapping."
     "If the government won't let them go," Nancy said, "what can you or the refugee group do?"
     "Ah," said the professor, arching his brows and holding up one long forefinger as he so often did when teaching, "that's the catch. The children are somewhere in Hungary. They are being kept in hiding by an organization of dedicated people who have sworn to get them safely across the border into Austria."
     "How?"
     "Somehow. I don't know and I won't until I get to Vienna. Then I'll be told how they plan to use me and Eric to get the job done."
     "Eric?" repeated the young sleuth, incredulous. "You mean Eric Nagy?"
     The tour leader nodded, then motioned to Eric who was seated several tables away. As the smiling young man rolled his wheelchair forward, the professor said, "Eric, I've let Nancy in on our mission. I'm sure you won't mind because she could be of great help to us. Anyway, she's such a good sleuth with a nose for clues that she would have figured it out all by herself within a day, at most."
     "Oh, wait a minute. Dr. Bagley," Nancy said, blushing. "Nobody is that astute."
     "I'm delighted to be associated with the beautiful Miss Drew," said Eric, smiling and looking very intently at Nancy, so intently that she felt herself blush more deeply and observed Ned, watching from across the room, shift uncomfortably in his chair.
     The professor nodded and grinned. "Yes," he said, "I knew, somehow, you'd feel that way. But back to business. Nancy, Eric got into this because his parents were born in Hungary. His family has always been very active in helping others escape from behind the Iron Curtain. Eric is now carrying on the tradition."
     As Dr. Bagley talked, Nancy's mind raced over the possibilities, wondering how a middle-aged professor with a leg wounded in the war and a young man confined to a wheelchair could possibly help refugees escape. Didn't such attempts always involve a great deal of running, jumping, and physical exertion? But it would be bad manners to ask and realizing she didn't have all the facts, the girl listened and said nothing.
     "It so happens," the professor continued, "that this particular mission involves someone very close to Eric—a thirteen-year-old cousin who is one of those ten children."
     "Excuse me." They looked up and saw Ned standing uncomfortably, trying to smile. "I just wanted to say that we're running pretty late and we don't have a bus driver anymore and I'd like to volunteer to drive everyone to Salzburg." Ned's eyes flicked from Nancy to Eric and back to the professor.
     Dr. Bagley smiled. "I appreciate your concern for the tour, Ned. Thank you. I'll accept your kind offer. And please pardon our rudeness in excluding everyone but I've got to discuss something confidential with Nancy."
     Ned nodded and moved off uneasily, allowing Professor Bagley to return to their main subject.
     "Now," he said, as he finished his coffee and started to prepare one of his numerous pipes which he could never keep lit, "I'd like to explain about the porter who tried to steal my luggage. You see, it was a ruse that backfired on me. I knew somebody was going to try stealing the luggage and I wanted him to."
     "What?" Nancy gasped. But before the professor could elaborate, Bess Marvin burst in the door, her eyes almost popping with excitement.
     "Nancy! Dr. Bagley! Hurry! The bus! The bus! Something's happening to it. I think it's going to explode!"