"We have a dead man here," stated Barth, pointing to Valdan's body. "Apparently, he had climbed up that ladder when something overcame him. Do you believe, doctor, that he could have succ.u.mbed to this same mysterious malady that has affected those two guinea pigs?"

"Certainly," responded Lagwood, promptly. "There is every indication of it. The fact, however, would be difficult to prove."

"Why so?"

"Because the victim is dead. We may a.s.sume, however, that he was overcome simultaneously with the guinea pigs. My belief is based upon last night's occurrence. Had any of those victims at Tanning's been upon a ladder, they would have fallen in the same manner as this man."

"Then you believe that the death was accidental?"

"In a sense yes. In a sense no." The physician's long face showed a furrowed smile at his own paradoxical statement. "I should say that the fall from the ladder was accidental. But I cannot speak for the condition which induced that fall. You are faced by the same problem that you found at Tanning's."

"That's right," a.s.serted Joe Cardona. "Commissioner, I've got a theory about last night. Four people going out all at once. It must have been some gas that knocked them out." He turned to Lagwood.

"What's your opinion on that, doctor?"

"I had the same idea," responded Lagwood, seriously. "In fact, I had planned to try vapor treatments in an endeavor to neutralize the blood conditions of the patients. But my observations in this laboratory lead me to believe that we may be concerned with some amazingly virulent bacillus, not with a noxious gas."

"That sounds incredible!" exclaimed Barth. "Last night, four persons were overcome simultaneously. Here we have the evidence of the guinea pigs, to indicate that Valdan was overcome by the same cause.

Cardona may be right, doctor. A gas -"

"What of these guinea pigs?" interposed Lagwood, indicating the crate upon the floor.

A SMILE showed upon Lamont Cranston's lips as Barth and Cardona turned toward the crate.

Commissioner and detective had forgotten all about the shipment that had been delivered. The guinea pigs in the crate were all alive.

"The hypothesis of a poison gas," stated Lagwood, "is one that I now find it necessary to reject. I shall, however, make experiments upon one of these rigid guinea pigs, utilizing a vapor as a neutralizer.

"But it is evident that a poison gas, loosed in this closed room, would have had effect upon all life simultaneously. None of the rodents in this crate show any signs of lethargy. Besides that, commissioner, there is another point to be considered. How soon after death was the body discovered?"

"Almost immediately," replied Barth.

"Was the door of this room opened or closed?" questioned Lagwood.

"Closed," stated Barth. "Valdan's a.s.sistant opened it and entered with the servant."

"Did either of them experience any dizziness?" "They made no statements of that sort."

"Which proves," concluded Lagwood, "that no noxious gas was present. In this small room - with no open windows - the atmosphere could not have cleared before those persons arrived."

"That is true," agreed Barth. "Tell us, doctor, what would you propose as the next step?"

"For my own part," responded Lagwood, emphatically, "I should like to return to the hospital and begin experiments upon these guinea pigs at once. This dead man is a problem for the police. My duty is to consider the welfare of four who are still alive."

"You are right," said the commissioner. "Cardona, call a cab for Doctor Lagwood. Tie up that box with the two guinea pigs. Human lives are still at stake."

The specialist departed with the guinea pigs boxed beneath his arm. The commissioner seated himself at Valdan's table and began to strum upon the woodwork while Cranston looked quietly about the room.

"A new quiz may bring the answer," speculated the commissioner. "Either Benzig or Crowder could have been in this room. Their meeting upstairs did not take place until some time after Benzig claims to have left here.

"Benzig might have remained; or Crowder might have been hidden in that closet. Benzig could have taken the newspaper; or Crowder could have failed to place it here. The hidden man could have attacked Valdan; then unbolted this door and left. Do you follow me, Cranston?"

"Yes," came the quiet reply.

"Leaving, the murderer could have unbolted the outer door to make it appear that someone had fled."

Barth was picturing a scene involving one of Valdan's employees. "The delivery men could hardly have had anything to do with Valdan's death. Why should they have made two trips here?"

This time, Cranston had no reply. He glanced at his watch and appeared surprised at the lateness of the hour. Barth sensed that his friend was anxious to leave. He arose from his chair.

"I can come back to the club by cab," declared Barth. "I doubt that the coming quiz would be of but little interest to you, Cranston. Should you care to learn about them, I can tell you of our findings when I see you at the club."

"Very well," agreed Cranston. "I believe that it would be best for me to leave, commissioner."

FIVE minutes later, Lamont Cranston's limousine rolled away from the home of Troxton Valdan. After a southward trip, it turned into a secluded side street. Stanley parked at his master's bidding. A blackened form emerged silently from the rear door.

The light clicked in The Shadow's sanctum. Hands appeared beneath the bluish glow. A soft laugh sounded as deft fingers began to inscribe written thoughts that faded in mysterious fashion. The Shadow was considering facts that he had noted at Troxton Valdan's.

Valdan. Guinea pigs.

To Commissioner Wainwright Barth, this written statement would have meant the connection that had been discussed with Doctor Seton Lagwood: namely, the simultaneous overpowering of the chemist and the rodents in the box upon the table. To The Shadow, however, it inspired a new deduction. Why had Troxton Valdan kept guinea pigs in his little laboratory? Obviously for experimental purposes.

Benzig had not been surprised at the delivery of a fresh supply. Therefore, The Shadow knew that Valdan must have been gradually eliminating the cavies that he kept on hand.

This indicated that Valdan himself had applied the paralytic treatment to the two guinea pigs in the cardboard box. The chemist was not a victim of the death sleep. The living guinea pigs proved that fact.

Instead, Valdan, with his secret experiments, was logically the discoverer of the gas that produced a rigid slumber!

Delivery men.

Two visits. Again, The Shadow laughed softly. He could see the purpose. Yesterday, men had come with boxes. Benzig had gone upstairs while they were in the laboratory. The men had taken the boxes away. But they had left one of the three and taken another in its place. They had stolen the complete supply of gas containers that Troxton Valdan had concealed beneath the table in his little laboratory!

Cardona had found a box with pieces of pipe inside it. Beside the box, a carpeting that had served to hide it from view. The box with its useless contents had meant nothing to Cardona; but it had meant much to Troxton Valdan. Opening the box, the returned chemist had learned that his precious chemicals had been stolen!

The newspaper.

The Shadow combined this new thought with an unfinished one - the matter of the second appearance of the delivery men. The first visit had been to accomplish theft. The second, to offset Valdan's discovery.

Last night, Valdan's gas had been tested. Seth Tanning and three others were the victims.

Today, Valdan was due to return. There was only one course open to men of crime. Valdan had to be silenced - forever. The second delivery - the crate of guinea pigs - had been a blind to enable a killer to conceal himself in the closet of the inner laboratory, there to await the return of Troxton Valdan.

Someone - either the killer or a member of the crew - had seen the newspaper upon Valdan's table. That journal had been removed. This was proof that someone in the crew - probably the killer - knew the contents of the box that had been stolen on the previous day. That same man might have been the one who had precipitated a gas bomb into Seth Tanning's apartment.

The murderer.

The Shadow was a.n.a.lyzing the final situation. He was picturing the attack upon Troxton Valdan. The chemist had returned. No newspaper had been there to give him an inkling that his stolen discovery had been used for crime. Yet he must have suspected trouble because of Benzig's report concerning the delivery men.

Valdan had brought out the hidden box. He had found it to be a subst.i.tute for the one that he had left. He had climbed the ladder, to see if his files were intact. He had learned that one - number 111 - was missing. Then the killer had attacked.

The murderer had chosen darkness. His work done, he had fled, probably fearing the prompt return of Benzig.

He had probably not seen the two guinea pigs in the cardboard box. He had made no attempt to turn on the light again.

That oversight marked him as a man of brute strength who lacked craft. The Shadow could see the scheming of a master brain; but he knew that the actual murder of Troxton Valdan had been left to an underling. The big shot was out of sight, trusting to crooks of gangster type to do his bidding.

THE bluish light clicked out. The Shadow had gone far in his a.n.a.lysis of crime. He knew that some crafty superfiend had learned of Troxton Valdan's experiments; that this schemer had called in the aid of ordinary criminals to gain the weapon that he wanted.

There had been strategy in last night's test. Had it failed, the stolen box might have been replaced.

Troxton Valdan would have been left in ignorance, to proceed with his experiments. But the test had succeeded; the result had been Valdan's death warrant.

A fading laugh trailed through the sanctum. That sinister taunt marked the departure of the black-garbed investigator. But its ominous challenge carried a thought as well. The Shadow, ready to wage war with men of evil, had considered the strength of his foe.

As yet, there had been no indication that those who had gained Valdan's secret possessed a means of protecting themselves against its power. Though their test had succeeded, crime must wait until they could guard against the boomerang effects which made others succ.u.mb.

Did friends of crime possess this second secret that they needed? If they did, The Shadow must act swiftly to offset their coming thrusts. If they did not, there would be time for The Shadow to prepare a well-formed counterstroke.

The Shadow's deductions had carried him to this final point. All else had yielded to his keen reasoning.

While investigators of the law remained perplexed by baffling mysteries, The Shadow had reached the period of action.

Crime was coming. Crime with a purpose. Preliminary strokes had involved men of the underworld. Such minions would be used in the thrusts that were to come. With this conviction, The Shadow had mapped his campaign. As yet, the odds lay with those who defied the law. But The Shadow, unseen, unsuspected, was swinging the balance to his favor.

CHAPTER VIII. PLANS FOR CRIME.

"LOUSY business."

Wolf Barlan growled this a.s.sertion as he glowered at Spud Claxter. The big shot was seated by the window of his living room, holding a morning newspaper on his lap. Spud, his shrewd face dejected, was eyeing his chief. Spud ventured a remark.

"The bulls ain't wise, Wolf," protested the lieutenant. "Zug got away with it. That's what you wanted, wasn't it? He croaked Valdan, didn't he?"

"Sure he did," returned Wolf, "but it's a wonder everybody else don't know it, along with us. Zug got the breaks - but he didn't make them for himself."

"He was smart when he swiped the newspaper."

"And dumb after that. He had every chance to make the whole job look like it was an accident. But he flivved it when he turned the lights out."

"Zug wasn't so dumb doing that," put in Spud. "Suppose something had gone wrong. Suppose Valdan had got away from him. If the lights had been on, the old geezer would have spotted Zug - andremembered him, maybe."

"Yeah?" questioned Wolf. "So Zug was kind of weak in the knees, eh? Thought maybe he was going to slip? I didn't figure he was yellow."

"Zug ain't yellow. He just played it safe. Putting out the lights left Valdan in a mess. He didn't make no trouble after Zug grabbed him."

"No. But Zug made trouble for himself. Why didn't he shoot the lights on again?"

"You'll be asking me next why he didn't walk off with the two doped guinea pigs that the papers are talking about. Who made the slip-up on them?"

"I didn't," growled Wolf. He paused suddenly as he saw a quizzical look on Spud's face. "What I mean is, I didn't figure that they were in the place. Listen, Spud. This wasn't the first trip Valdan made out of town. Every other time he went, he took his guinea pigs along with him. The ones that he'd ga.s.sed. You understand?"

"Well, if he didn't have them this trip -"

"He did have them. That's the catch to it. But he must have doped a couple more before he left. That was something we didn't figure on - something I didn't know about."

"All right," grinned Spud. "Zug didn't figure on the light either. And what's more, Wolf, it wouldn't have made so much difference. He couldn't have bolted that outer door in back of him. Maybe Zug ought to have croaked this fellow Benzig, along with Valdan."

"The police are holding Benzig," observed Wolf, somewhat mollified. "Material witness, the papers say, but I'll bet they've got the guy under suspicion. It would have been better though, if the lights had been on."

"Anyway, we got a break. It was a bad set-up, the way Zug left it. Lights off, bolts loose, two doped guinea pigs. Say - it's lucky we shipped that crate of live guineas in there instead of the gla.s.s beakers I thought about sending.

"They've hooked up Valdan's death with those people we knocked out the night before. But they're off the track of gas. That was on account of the live guinea pigs. Did you read this statement by Doctor Lagwood?"

"Yeah," Spud chuckled. "The croaker pulled a bull, didn't he? You couldn't blame him though. He thought he was pretty smart, I guess, when he said any gas would have doped the whole lot of guinea pigs instead of just two."

"It worked out nice for us," a.s.serted Wolf. "Gave Lagwood a big boost, which means there won't be a lot more medicos horning in on the case."

"Only the one guy to watch," added Spud. "Well - when you want the croaker rubbed out, pa.s.s the word."

"I'm not worrying about Lagwood," observed Wolf, narrowly, as he lighted a cigarette. "The guy is going to be worth more to us than your whole gang. Say - he'll rate ace high when those saps wake up around midnight. Everybody will think he brought them out of the trance. They won't know that the crowd was due to wake up in forty-eight hours. That's the way the gas works." "But suppose Lagwood figures it out?"

"What difference does that make? Do you think any croaker would go around refusing credit? You bet none of them would. That sawbones will hog all the medals he can get."

"That's right, Wolf. He'll probably figure he woke up the dummies anyway. But just the same - I can't see where Lagwood is going to help the game. Skeet slipped me the word that he's been working heavy on these mugs that we put under."

"Yeah?" Wolf's inquiry came with a puff of cigarette smoke. "I was just going to ask you about Skeet.

He's got more brains than that guy Zug. What's Skeet got to say?"

"He landed that job up at the hospital. Pushing wheel chairs in and out of a store room. Bringing up packages. Running errands. Sort of a general handy man. Got a look in on Doctor Lagwood's experimental room, but didn't have a chance to snoop around it. I told him to lay off."

"That's right. Has he seen his nibs?"

"Yeah." Spud pulled a sheet of paper from his pocket. "Lagwood sent him down to a drug store to bring back some prescriptions. Here's a list of the stuff."

WOLF received the sheet of paper. Instead of being listed as prescriptions, in the usual pharmaceutical fashion, the items bore special names that were apparently of Doctor Lagwood's devising. These were odd abbreviations and each bore a number.

"That's funny," observed Wolf. "Wonder why the medico made up a list like this?"

"He explained it to Skeet," stated Spud. "Told him that if Hoffer - that's the old druggist - wasn't in the shop, to give it to anybody there. Said he always had his preparations marked so that a dumb clerk could locate them."

"Not a bad idea."