Herr Domber led the way from his shop and laboratory to the street entrance where a car was waiting. He scowled at the guards outside his door and shouted, "Heil Hitler!" Then he marched down the walk to the car. This time no uniformed guards went along. There was just the driver, Domber, and Stan.

Stan was beginning to get the idea that the Dutch Quisling disliked the military. But he was not fooled into thinking Domber did not have his own henchmen. The driver of the car was a powerful fellow with beetled brows and scowling face. As soon as they pulled away from the curb, another car slipped in behind them and never left them until they parked outside a walled enclosure.

They were getting out of the car when a German military machine roared up and stopped. Two officers got out and moved stiffly toward the spot where Stan and Domber stood.

"Heil Hitler," Domber said. Then he opened up with an angry flow of German.

The officers snapped back at him and a heated argument raged. Stan gathered the officers were angry because Domber had taken Stan out without a proper armed guard. Apparently Domber won the argument. The officers saluted and made off.

"Such fools. They fear you would escape," Domber explained. "I have told them you would not get a hundred yards before you would be killed. No one has ever escaped from the Bloodhound."

"Bloodhound?"

"That is a pet name my Dutch friends have given me." He smiled at Stan. "But come, we are being delayed."

A gate opened and a man in coveralls came up to meet them. Domber spoke to him and the man walked with them to a locked door in a second wall. Producing a key, he opened the door and let them through.

Stan was startled by what he saw. There was a sunken runway leading into an underground hangar. Domber beamed.

"Not a bomb ever falls here. Above our shops there is a church and a schoolhouse. We do much valuable research here and cannot afford to be disturbed."

Stan looked along the runway. It ended abruptly at a steel fence, but a roadway went on in a twisting course, making detection of the runway difficult.

"Very clever," Stan said.

"I was sure you'd appreciate it," Domber said. "Now we'll have a look at the P-51."

They entered the underground hangar by going down a shaft in an elevator. Stepping out of the elevator Stan saw a well-lighted and spacious hangar. Various planes stood along one high wall. There was a Fort, a Wellington, two Spitfires, a Lockheed Lightning, and at the far end in a wide shop space stood a new P-51. Her nose was pointed out toward the runway and she looked ready to glide out from underground and take off. Domber laughed.

"I'm sorry, but it can't be done," he said as though Stan had spoken his thoughts out loud.

"Can't blame me for thinking about it, can you?" Stan asked.

They walked over to the fighter. She had been patched up and looked airworthy enough.

"Mind if I go up?" Stan asked.

A dozen men working in the shop stood watching. "No, go ahead," Domber said.

Stan climbed up and into the cockpit. A glance showed him that there had been considerable instrument damage which the German mechanics had not been able to repair. He noticed at once that the engine was hooked up to a small portable gasoline tank. That meant she had no fuel in her except just enough to make test runs of the engine. It probably was a fire hazard measure, but it also was one reason why Domber was so willing to let Stan get into the cockpit.

The other reason Stan soon discovered. Looking out, he saw on each side of the opening to the runway, batteries of aircraft cannon. Those guns could lay a concentrated cross fire over the runway so deadly that any plane would be blown to bits in a minute.

Stan climbed down out of the cockpit. He faced Herr Domber. "Just what was it you wanted me to do?" He had to stall for time, more time.

"You will assemble and repair the supercharger on that plane. Every tool you need will be at hand, and if you need an assistant I will furnish you one who speaks English." Herr Domber was smiling as he spoke.

"That's a big order," Stan said.

"My experts could do this, but it might take several weeks and we do not have that much time. We have such a ship as this one. All we need is a supercharger to make it the best ship in the world. Naturally I am anxious and do not wish to lose any time."

"I'll need an English-speaking helper. I may have to have parts made and I do not run a lathe," Stan said.

Herr Domber called a man over to him. After listening for a few minutes the man left. He returned a few minutes later with a youngster not more than eighteen years of age.

"Swen, you will be Lieutenant Wilson's assistant. Help him in every way you can. You are under his orders," Herr Domber said.

"Heil Hitler," Swen said and saluted. He was a blond, curly-headed kid with a ready smile. Stan grinned at him and said:

"We'll get along."

"You may talk freely to Swen," Domber said. "He is a tested party man, but he does not like killing, so he is a mechanic. I have to watch him to keep the generals from stealing him and sending him off to Russia to fight." Domber laughed, but Stan saw fear come into the boy's eyes.

"Anyone else speak English in the shop?" he asked. "I might want another man."

"No others," Domber said. "Now we must get to work."

Stan was supplied with a locker and a pair of coveralls. He was taken to a special room in the shop. There he found parts from P-51's recently shot down. The smaller shop was completely equipped. Three other men worked at benches before a window. Stan was assigned to a vacant bench. Before him lay part of the new dual turbo-supercharger. Other parts were stacked on a table.

"Know anything about one of these gadgets?" Stan asked Swen.

"Gadget?" Swen repeated in a British accent.

"Yank word for machine," Stan explained.

"No, I have never seen one before," Swen replied.

Herr Domber stood around for a little while, then made off. Stan grinned at Swen. He had decided to work upon the kid. There might be a chance to do something. Swen, like most young Germans, was deadly afraid of being sent to the Russian front. It might be that he secretly hated the men who bossed him.

At the next bench a tall mechanic was working with a part from a Spitfire. Stan moved over to the edge of his bench.

"Hand me that wrench," he said to the tall German.

The German reached over and handed Stan the wrench. Suddenly his face became very red and he spoke angrily in German.

"Thanks, buddy," Stan said. "I'm glad you speak American."

The German shrugged his shoulders and went on working. Swen looked at Stan and said:

"I am your helper. I could have handed you that wrench."

"I just wanted to be sure Heinie, here, could understand everything we say. I noticed that he was just playing with that oil gauge. It's an old type that's been out of use for four years."

The tall German's face got redder. He growled something and moved away. Stan figured he was going to report he had been spotted.

"Now, Swen," Stan said, "we're going to be friends, you and I."

Swen looked scared. "Heil Hitler," he said. "I am not to be your friend."

"You won't get hurt," Stan said softly. "Just tell them everything I tell you when they question you tonight."

"They will kill you," Swen said in a low voice. "Herr Domber poisoned the other one. He will do the same to you."

"Tell me about it quickly. They won't be leaving us alone without a spotter very long," Stan said.

"I do not know how it was done. I heard the Gestapo men laughing about it. The British flier thought he was going to get away. He fixed up his plane and had gasoline enough for much testing. But after he had it running and they learned what they wanted to know about it, he just fell over dead."

"That is quicker than working it out by themselves. Not much, but a few days," Stan said grimly.

At that moment the tall German who had been working at the next bench came running up. He was out of breath when he halted before Stan.

"I am to be your helper." He turned upon Swen. "Get out into the shop."

"Sorry to lose you, Swen," Stan called after the boy. He turned to the new helper. "They sure sent you back on the run. Did you get a good skinning?"

The German scowled at Stan. "I am to take orders," he muttered.

Stan laughed. The softhearted Swen had been planted on him. They were supposed to get chummy while the tall mechanic listened and picked up anything of value which might be said.

"What am I supposed to call you?" Stan asked.

"Hans," the mechanic said shortly.

"Well, Hans, we'll have a try at assembling this thing," Stan said.

Stan worked on the supercharger all that afternoon and convinced himself that he could fit it together and make it work. Toward evening Herr Domber came back. He halted beside the bench and looked at the machinery there.

"You have had some success?"

"I don't know," Stan said innocently. "I'll have to try it out on the ship."

"Certainly," Domber agreed. "Of course. When will you wish to try it out?"

"Tomorrow afternoon," Stan said.

"If you worked tonight you could try it out in the morning?" Domber suggested with a leer.

"Yes, I guess so," Stan said.

"Fine. I know you won't mind working tonight."

"Of course not," Stan said and felt an itch to lay his fist against Herr Domber's receding chin.

"You will honor me by having dinner with me tonight?"

"Certainly," Stan said and laughed. He might as well live high while he could live.

As they went out to enter Domber's car, Stan asked, "Why do you go to all of this fuss? I can't understand you Germans. There was a lot of fuss in planning to let us escape. Now you are putting on a big show for me. You could get results without it."

"We have much humor," Domber said. "I have my own little jokes and enjoy them." He smiled at Stan.

Stan thought about the R.A.F. flier who had been poisoned after he revealed what Domber wanted to know. He decided Herr Domber was a bit of a maniac as well as an enemy and a traitor to Holland.

After an excellent dinner Stan was taken back to the job. Herr Domber was in high spirits. Hans was waiting at the bench. Stan saw at once that the mechanic had been trying to fit the machinery together. With a grin he fished several parts out of his coverall pocket and set to work.

As he worked he began to plan. If he was to be poisoned, it likely would be done shortly before the tryout. He would have to watch closely. He would drink nothing and he would eat nothing. And he would keep two vitally important parts hidden until he had to put them into place. He also would be very careful no one bumped into him and jabbed him with a hypodermic needle. The last method of poisoning did not seem to fit in with the character of Herr Domber. His method would be cunning and crafty, and it would be done with a lot of showmanship.

Nobody but Herr Domber, Stan decided, would have thought up such a crazy method of saving a few days time, and of making away with a prisoner of war. If he was called to face charges after the war, he could claim Stan Wilson had turned traitor to his country and disclosed secrets before meeting an accidental death.

Stan looked at the machine on the bench. He was taking chances with valuable secrets, but if he escaped he would be able to stop a mass slaughter of British and American planes and men, perhaps even a gas attack upon England. He decided it was worth the risk.

"You work very slow," Hans complained.

"You're here to take orders," Stan snapped.

Hans jumped and scowled at Stan. He was so used to being snapped at that he reacted without thought. Stan laughed.

"You jump like monkeys when they yell at you, don't you?" he said.

"Pig," Hans muttered under his breath.

Stan went to work again. At twelve o'clock he took off his coveralls and slipped several parts into his coat pocket.

"Tell the boss I'm ready to go to bed," he said.

Hans made off and while he was gone Stan did a few things to the supercharger. Hans came back quickly.

"Herr Domber will call for you," he said, then seated himself and lighted a cigarette.

Domber appeared a half-hour later, dressed in evening clothes. He was beaming.

"You have everything ready for a tryout in the morning?" he asked.

"Everything," Stan assured him.

"I must have a look at the machine," Domber said. He walked to the bench and spent a half-hour studying the supercharger. Finally he turned to Stan. "How much testing will be required to adjust it?"

"It can only be adjusted by running the motor," Stan said and did not smile. "I should say the plane could be ready for flight by afternoon."

"You will run it that long?"

"It may take even longer," Stan said. "This is a delicate bit of machinery and I am not too familiar with it. I have only had a general course in its construction."

"In that case we will have the tanks connected and filled with gasoline." Domber smiled broadly.

"That will save time, and I understand that's what you are interested in," Stan said.

"Time, yes, we have to work fast."

Stan grinned. He knew that Herman Goering's Air Ministry was wild with fear and grasping at every straw of help they could get for their fighter planes. They had to have something that would stop the Fortresses and Liberators, or their cities would be destroyed, and they had to have it quick.

"Haven't you ever thought that I might sabotage this job?" he asked.

"I think not," Domber said. "I am a student of the human mind. When I have studied a man I know just about what he will do. I know you do not wish to be turned over to the Gestapo and given the treatment they use to get information."

"No, I guess I'm not that much of a hero," Stan said.