"'Sides you two," he declared, "only one stranger has been in this here building today." "What did that one look like?" Doc asked.

"He was kinda tall, middlin' thin, and had one of them there movie mustaches. Just looking at it made me kinda want to reach out and jerk it off."

"Did the fellow have freckles?"

"Yes siree. Come to think of it, he did."

"Caldwell," said Doc.

"It's his description," Griswold Rock agreed. "Pere Teston is a wizened fellow, and no one would ever forget his weird, dead-looking face. So it wasn't Pere Teston."

Doc made no comment on this. "They were afraid the telegram would be evidence against them,"

Griswold Rock continued after a brief interval. "Caldwell came and got it. I tell you I'm worried! They're after me and they're clever."

"Caldwell will not bother you," Doc advised. Griswold Rock looked surprised; "But he is one of the gang."

"He is also dead." With a few terse words, Doc described the demise of Caldwell.

"Caldwell was stuck with a thrown knife as he reached the log," Doc finished. "He toppled to the quicksand. The murderer escaped. There was no clew to his ident.i.ty."

"What about the killer's tracks?"

"They were made by extremely large pacs. The size indicated the killer was wearing them over his shoes."

"That sounds like Pere Teston!" Griswold Rock e.j.a.c.u.l.a.t.ed. He shuddered. "That shriveled fiend has small feet."

Doc's four men arrived at the hotel. It was decided to make the hostelry their Trapper Lake headquarters.

Doc Savage inquired for a long distance telephone connection with New York City, and learned there were no phone wires out of town.

Doc set up his radio apparatus. Working through a station on Long Island, which transposed his words from the ether to land-line, he got in contact with Renny.

"How's the excavating going forward?" he asked. "Better than expected," Renny reported. "Doubled the working crew this morning. I located a hydraulicking outfit such as they use for gold mining in the west, and we're using powerful streams of water to wash the hill away."

"Did you check up on the finger prints found on the gate of Griswold Rock's estate?"

MONK AND Ham exchanged glances which, for once, were surprised instead of mutually insulting looks. Here was an angle upon which they had not known Doc was working.

"I checked the prints," Renny reported. "The cla.s.sifications were broadcast to leading police departments." Renny paused at the other end to give an order to some one, probably an a.s.sociate in the excavating work.

"Here's a strange thing about the finger prints, Doc," he continued. "They were all of men who have escaped from prisons within the last few months."

"All from one particular prison?" Doc asked.

"No. Several different States. One bunch got out of the Jefferson City pen, in Missouri. Another broke out of the Oklahoma hoosegow at McAlester. All got outside aid in escaping."

"This may be significant," Doc remarked.

"Here's something else that may be, too," Renny reported. "The police have a record on Caldwell. His picture is in the rogue's gallery. He has served two prison terms."

"For what crimes?"

"He's a crook who makes a specialty of getting other criminals out of jail. He was caught doing this a couple of times. That's how he happened to go to the hoosegow."

"Anything else?" Doc asked.

"Nope."

The radio and land-line consultation ended with that Doc Savage turned to his friends. They eyed him expectantly. It was Doc's custom to a.s.sign his a.s.sociates work which fell in their respective lines.

"Monk," Doc said, "you'll fix up chemical bombs. Make them strong enough to knock out an elephant Use a gas which produces unconsciousness, rather than fatality."

Monk nodded. The job was up his alley.

Doc a.s.signed work to Ham -- the lawyer was to delve further into the records of the Timberland Line railroad, m an effort to see what he could find.

"If you wish, you can a.s.sist Ham in this matter," Doc told Griswold Rock.

The plump man trembled violently, but nodded.

"Very well," he groaned. "It seems I had best help you fellows, greatly as I am frightened. I will never feel at ease until this devil, Pere Teston, is brought to justice."

Johnny, the bony geologist, whose learning naturally included an understanding of earthquakes and the seismographic method used to study them, was to plant sensitive listening devices in the earth. Long Tom, the electrical wizard, was to a.s.sist in this.

"The idea is to trace the direction which the footsteps of these prowling monsters take," Doc explained.

The remainder of the afternoon was spent in following Doc Savage's suggestions.

The homely Monk possessed a remarkably compact portable chemical laboratory which he always took upon expeditions of this sort. Long Tom, the electrical wizard, likewise carried an a.s.sortment of devices.

The two experts utilized their equipment to carry out Doc's suggestions. Doc Savage spent some time working with devices which he himself had brought. During this interval, he secluded himself in a room of the Guide's Hotel.

When the bronze man appeared, some time later, he was placing in a pocket objects which resembled ordinary .410 gauge shotgun sh.e.l.ls.

Ham and Griswold Rock returned to the hotel near nightfall.

"I talked to conductors on some of the Timberland Line pa.s.senger trains," Ham reported. "They gave me some interesting dope. It seems that they have noted some very tough-looking pa.s.sengers on their trains during recent months. These fellows are obviously criminals. All of them got off at Trapper Lake."

Ham paused; he could not resist an urge for dramatics. "These tough-looking fellows were always in the company of a certain man!"

"Don't beat around the bush!" growled Monk, who was listening. "Who was the guy?"

"Caldwell!"

Griswold Rock wrung his fat hands in fright. "I cannot understand this. Caldwell has been extricating criminals from prisons and bringing them to this vicinity. Why?"

That was the mystery.

It was deepened somewhat by information which Doc Savage secured by radio, later in the day. A fresh crop of "Beware the Monsters!" advertis.e.m.e.nts had appeared in newspapers all over the country. These had been mailed from Trapper Lake.

Doc consulted the Trapper Lake postmaster. The latter was reluctant to speak at first, but Doc produced credentials signed by the highest of government officials. The postmaster turned into a fountain of information.

Yes, he had noted a man mailing many letters to newspapers all over the United States. Yes, he could describe the man.

He described Caldwell.

Monk, having completed his chemical bombs, did some prowling about town. The homely chemist was an excellent mixer. When he returned to the Guide's Hotel he had some information.

"Caldwell seems to have pulled one of his jail deliveries right here in Trapper Lake," he declared. "The local calaboose was broken into about a year ago. A fellow called Nubby Bronson was taken out. The man suspected of engineering the jail delivery answers the description of Caldwell."

"Who was Nubby Bronson?" Doc asked.

"A local bad man," Monk explained. "The fellow had served several short prison terms for petty crimes."

"Was he in for a serious offense when the jail delivery took place?"

"That's the strange part. He was serving thirty days for stealing traps. The jailer said he seemed satisfied with his lot. They were surprised when the break took place."

Doc Savage considered this for a time. "The inference is that Nubby Bronson did not want to get out of jail bad enough to hire his own delivery?" he queried at last.

"That's the idea," Monk agreed.

Griswold Rock gestured astonishment with his fat hands. "But why should Caldwell break into jail to free a man who did not particularly want to escape?"

If Doc knew the answer to that question, he gave no indication of the fact. He maintained silence.

THE GUIDE'S Hotel, they discovered, set an excellent table. Strangely enough, it was the thinnest man in the party -- skeletonlike Johnny -- who was the heaviest consumer of food.

"I wonder where the stuff he eats goes to," pondered homely Monk when Johnny, having eaten prodigiously, arose from the table looking, if anything, thinner than before.

Ham scowled at the pleasantly ugly chemist. "One doesn't have to wonder where your grub goes to. It's converted into hair."

Later, Doc employed his radio transmitter to obtain a connection with New York City. He sought to locate Renny.

"Mr. Renwick left New York by plane about an hour ago," reported one of the big-fisted engineer's a.s.sociates.

"Left the city!"

"That is correct."

"Why?"

"The excavators uncovered some object late this afternoon," the man in New York explained.

"What was it?"

"No one but Mr. Renwick knows. It was he who found the thing. He ordered all work to cease, and finished the digging personally. He wrapped his discovery in canvas and carried it away. I believe he took it with him in his plane."

"In which direction did he head?"

"There was something said about northern Michigan, I believe."

Doc Savage broke the connection.

"Renny found something important," he informed the others. "He is rushing it up here by plane."

"Then we should hear from him before morning," Monk declared.

Chapter 18. THE TERROR THAT SWAM.

ALTHOUGH THERE were no long distance telephone lines, Trapper Lake itself boasted a local phone service. Rooms in the Guide's Hotel were fitted with instruments.

It was slightly past midnight when the bell in Doc's room snarled. The bronze man scooped up the receiver. "They've attacked Renny!" yelled a shrill voice.

"Who is this?" Doc countered.

The voice was one he had never heard before. The words sounded as if sawed out by a high-pitched violin string.

"Renny is fighting a mob in a patch of woods about a mile north of town," continued the shrill voice.

"Who are you?"

"Renny says he must have been unlucky. He landed right among the gang. I'm calling from the edge of town."

"Are you going to identify yourself or not?" Doc demanded grimly.

"I live in a cabin close to where Renny's having his fight," said the informant excitedly. "He gave me fifty dollars to come and call you."

Doc Savage started to ask questions. A click denoted the receiver had been deposited on the hook at the other end.

"Ham -- watch Griswold Rock," Doc ordered.

The fat railroad man had retired to his room, but he now appeared in the door.

"That is very kind of you," he said earnestly. "I would be terrified if one of you gentlemen was not near by for protection."

"Long Tom -- Johnny," Doc asked. "Have you got your seismograph devices all set?"

"Sure."

Homely Monk had been listening. A slow grin overspread his features as he saw that he was to accompany Doc.