We drop in, ask for Chahda, wait a while, get a note, and walk right into the arms of a reception committee. That's mighty good organization."

"They had plenty of time to get the junk ready for us," Rick pointed out. "We sat in Charlie's and cooled our heels for a long while."

"We should have had knives a foot long." Zircon smiled. "Then we could have given ourselves a manicure, like the Portuguese who left right after we arrived." He put his key in the lock and pushed the door open.

Rick had a confused impression of wild sounds, then something crashed into him and he landed flat on his back. As he scrambled to his feet, plaster showered down on him, and his ear separated the sounds. From within their room, a voice screamed, "Watch out! Take cover!" There was a blurred racket, as though a giant was running a stick along a monster picket fence at jet speed. Scotty was yelling something and Zircon was bellowing with rage. Then the thunderous st.i.tching noise stopped.

All three of them started into the room at the same time, and Rick reached the door first. It was dark in the room, but in the faint light from the hallway he saw two figures struggling. He acted without thought. On a dresser just inside the door he had left a big flashlight.

He grabbed it, jumped into the fray, and brought it down on the head of the man on top. The man slumped.

With a catlike twist the man who had been underneath wriggled free. Rick started to say, "What's going..." Then an open hand drove into his face and pushed him backward into Scotty and Zircon. The three of them fought for balance as Rick's a.s.sailant ran to the window, leaped out on to the fire escape, and was gone.

Scotty snapped on the light just as the man Rick had slugged staggered to his feet, blinking. He was of medium height, with a thin, dark face.

He was dressed like a seaman, and apparently he was a Eurasian. Black eyes blazed at the three of them.

"Shut that blasted door! And bolt it!" the man commanded.

Zircon bellowed, "Don't be giving us orders! Explain..."

"I'm Carl Bradley," the man said.

Rick swallowed. Of the two men in the room, he had lowered the boom on the wrong one!

Scotty shut the door and threw the bolt.

"I've got to talk fast," Bradley said. "The hotel people will be up here in a few seconds and I don't want them to find me. It would mean too many explanations, and the police would want a statement I'd rather not have to give."

He straddled a chair. "I suppose you've guessed that I was the Eurasian with the young Englishman. It was just luck I picked him up, and more luck that we found your rickshaw coolies. Long Shadow's men had you, and Long Shadow was watching. That's why I faded when you got ash.o.r.e. I intended following him, for once, instead of being followed myself.

About the only thing I don't know about him is his secret headquarters.

I didn't think I'd be able to get here, so I whispered to one of you that I'd phone. Well, Long Shadow led me here, up the fire escape. We came by a rather roundabout route, stopping while he ate. I suspected it was your room, but I didn't know for sure. He came in. I crouched on the fire escape. Didn't know what would happen, of course. Then we heard voices. I say we--he didn't know I was here, of course. He hauled a Schmeisser machine pistol from under his coat and slipped a clip in.

There was just enough light for me to see the outline. It's distinctive."

A queer little shudder zipped down Rick's spine. A Schmeisser! It was the pistol known as the "burp gun," that sprayed slugs like a hose. No wonder he hadn't recognized the sound! He kept his eyes on Bradley, intent on what the slender JANIG man had to say.

"I yelled out a warning," Bradley went on, "and jumped through the window at him. Didn't dare take time to draw my gun. I kept yelling, hoping one of you would give me a hand. He's wiry as a thuggee bandit.

Only I got a lump on the head instead."

"I'm sorry," Rick muttered.

"The damage is done and he's gone. Now I'll have to locate him again, if I can. Meanwhile, write this down. Quickly. I think I hear voices coming down the hall."

Scotty whipped a pencil and an envelope from an inside pocket.

"See the consul general. I've talked with him. He will give you a rubber boat and a Nansen bottle I've picked up. Outfit for the trail, and have plenty of weapons. Fly to Chungking and check in with the consul there.

Ask him to give you a reliable guide. You're going to Korse Lenken.

That's in Tibet." He spelled the name. "Chahda has gone on ahead. I'll follow. That's where the heavy water is coming from, I'm pretty sure.

Chahda will check up. You can help him, then make tests to be sure it's really heavy water. Maybe you can do something about the source of the stuff. You'll have to see when you get there. I've got part of the story about what's being done with the water, but not all of it."

There definitely were voices outside now. The burp gun had brought the hotel people. In a moment there was a hammering on the door.

Bradley walked to the window. "You can let them in after I've gone. Any questions? Quickly!"

"What's the Nansen bottle for?" Zircon demanded.

"I don't know. I only know that Long Shadow bought five of them."

Bradley threw a leg over the window sill and grinned at them. "Leave me out of any story you tell. I need a free hand for the next few days. And the less the police know about me the better for all of us." He hesitated as the pounding on the door grew louder, then a key grated in the lock. "I can tell you this," he said softly. "You can forget about an industrial plant. This is something else we're up against."

Then he was gone.

"Open the door," Zircon said. For the first time, Rick saw that the big scientist gripped his right arm just below the elbow, a red, sodden handkerchief balled in his left hand.

"You're wounded!" He jumped to the scientist's side.

"A scratch," Zircon said. "But it saved our lives. Tell you about it later. Open up, Scotty."

Scotty threw the door open and the English night clerk, three Chinese policemen, and half a dozen coolies piled in.

"What's going on here?" the clerk demanded. "What happened?"

"Nothing serious," Zircon said calmly. "There was evidently a bandit in our room. We opened the door and he fired with his submachine gun. Then, when he saw he hadn't killed us, he fled."

It wasn't a very convincing story. Rick saw suspicion in the faces of the hotel people. He threw in his nickel's worth. "What kept you so long? We've been trying to phone." He had a hunch the switchboard coolie was one of those in the room. Probably everyone on duty had raced up.

"We heard nothing downstairs," the night clerk said. "The floor coolie came down to get us. He took his time about it. Why was your door locked?"

Zircon tried hard to look sheepish. "I guess we must have bolted it in the confusion. Then, when you knocked, we tried to open it. It was a few seconds before we realized the bolt had been thrown and the door couldn't be opened unless the bolt was withdrawn. And the confounded thing stuck."

"Why didn't you yell?" one of the policemen demanded.

"Possibly you were yelling so loud yourselves you didn't hear us,"

Zircon said mildly. "You were making considerable noise."

The clerk frowned. "The manager will have to hear about this," he stated. "I doubt that he will believe your story. You may even be asked to pay damages."

Zircon drew himself up to his full height. "The day we pay damages for the privilege of being shot at in this disreputable dive you fatuously call a hotel will be the day Hong Kong sinks beneath the sea like Atlantis. Now have the goodness to clear out and let us get some sleep."

The clerk's face was scarlet. Rick tried to hide a grin.

"You'll have to make a formal statement to the police," the clerk snapped.

"In the morning," Zircon said. "In the morning we intend to see the American consul. You will hear more about this incident than you expect, my dear sir. Now clear out. We need our sleep. This has been most unsettling."

One of the policemen pointed to Zircon's bloodstained sleeve. "But you need medical attention, sir."

"I happen to be a doctor," Zircon said. That was true enough, but he was a doctor of science, not of medicine.

"You expect to treat yourself?" the clerk asked incredulously.

"Nothing to it," Zircon boomed. "A trifle. Why, once, when hunting in Africa, I had my back clawed by a lion. I st.i.tched the wounds up myself."