"That isn't Ned!" cried Jack's voice, in a moment.
"Don't let him get away! He's been up to some mischief!"
That was Frank Shaw's voice.
"Soak him!"
That could be no one but Jimmie!
Ned, groping about in the darkness, heard the voices faintly. Heseemed to be submerged in a sweep of pounding waves, the steadybeating of which shut out all individual sounds.
He knew that he staggered and stumbled as he walked. Moving across thefloor his feet came in contact with some soft obstruction lying on therug and he fell down.
There was a strange, choking odor in the place, and he groped on hishands and knees in the direction of the shelf where his searchlighthad been left. His senses reeled, and for an instant he lay flat onthe floor.
Then he heard the boys clambering down the stairs from the conningtower and called out, feebly, yet with sufficient strength to makehimself heard above the sound of shuffling feet.
"Go back!" he cried. "Don't come in here! Leave the hatch open, andlet in air. Go back!"
Jimmie recognized a note of alarm, of suffering, in the voice of hischum and dropped headlong into the black pit of the submarine. Nedheard him snap the catch of a searchlight, and then, dimly, heard hisvoice:
"Gee!" the voice said. "What's comin' off here?"
The round face of the electric searchlight showed at the end of acylindrical shaft of light which rested on Ned's face, but the boy didnot realize what was going on until he felt a gust of wind and adrizzle of rain on his forehead.
Then he opened his eyes to find himself on the conning tower of thesubmarine, with the boys gathered about him, anxiety showing in theirspeech and manner. It was too dark for him to see their faces.
"You're all right now," Jimmie said. "What got you down there?"
Then Ned remembered the sudden extinction of the lights as he moveddown the stairs, the stifling, choking odor below, and the deadly gripof suffocation which had brought him to the floor.
"Go back into the boat," he said, gaining strength every moment. "I amanxious about Lieutenant Scott."
"We've just come from there," Frank said. "We've done all that can bedone for him."
"What do you mean by that?" demanded Ned, moving toward the hatchwhich sealed the submarine.
"The poison which keeled you over got him!" Jack said.
"Do you mean that he's dead?" asked Ned, a shiver running through hisbody as he spoke.
"I'm afraid so," was the reply. "We got you out just in time. Youwould have perished in a moment more."
"Dead!" said Ned. "Lieutenant Scott dead! And he was so gay and sofull of life a few moments ago!"
Jack, who had left the little group a moment before, now returned.
"The poison seems to have evaporated from the interior," he said, "sowe may as well go below. I'll go ahead and turn on the lights." Thebody of the naval officer lay in a huddle at the foot of the stairsleading to the conning tower, just far enough to the rear so that thefree passage was not obstructed. With all the lights turned on andevery aperture which might transmit a ray to the world outside closed,the boys, after placing the body on a couch, began a close examinationof the boat.
There were no wounds on the body, so it seemed that he had died fromsuffocation. There was still a sickening odor in the boat, but theconstant manufacture of fresh air was gradually doing away with this.
The door to the room where the dynamos and the gasoline engine weresituated was found wide open, and Ned instructed the boys to leave itso and leave everything untouched.
"The first thing to do," he said, "is to discover any clues theassassin may have left here. It is an old theory that no person,however careful he or she may be, can enter and leave a room withoutleaving behind some evidence of his or her presence there. We'll soonknow if this is true in this case."
"There was some one in here, all right," Jimmie said. "He passed us onthe conning tower, skipping like to break the speed limit for thecity. I tried to trip him as he passed me, an' got this."
The lad turned a bruised face toward his companions. In the confusionno one had observed the cut on his cheek.
"You did get something!" Jack exclaimed. "Why didn't you say somethingabout it?"
"Nothin' doin'!" answered the boy. "Only a scratch!"
Notwithstanding the boy's claim that the wound was of smallimportance, Ned insisted on its being dressed at once.
"Now," Ned said, after the cut had been properly cared for, "what sortof a man was it that passed you boys on the conning tower? Thecircular platform is so small that he must have crowded you prettyclosely when he stepped out."
"He did," Jimmie answered. "I thought it was you, and stepped aside tomake room for him."
"And then?"
"I had a feeling that it wasn't you. Then, he was makin' for the wharfso fast that I thought it would do no harm to have a look at him, andso called out."
"Then's when you got the slash across the cheek?"
"Yes; he cut me then."
"What about the size of the fellow?" asked Ned.
"Oh, I should think he was slender and light, the way he bounded offthe platform and made for the wharf."
"Do you think he went there to kill Lieutenant Scott?" asked Jack, amoment later.
"It is more probable that he came here to put the Sea Lion out ofcommission," Frank replied.
"I'll bet well find somethin' all busted up!" Jimmie predicted.
"Ned can soon determine that," Jack remarked.
"Yes," Ned went on, "but the first thing to do is to see if thismurderer left any visiting cards here. After that, we must notify theCoroner and have the body removed."
Ned went into the dynamo room and looked about.
"Here is where any enemy would have to do his work," he said, "so wemust look for clues here. Keep your hands off the machinery, for hemay have left finger marks somewhere."
Ned searched long and carefully without reward. Finally he turned tothe waiting boys.
"There's quite a lot of waste lying around," he said. "Secure everyfiber of it and examine it under the microscope. You would betterattend to that, Frank, as you are familiar with the instrument. If youdiscover anything foreign to a place like this, let me know."
While Ned continued his search about the interior of the submarine,Frank busied himself inspecting the bits of waste the other boysbrought to him. At last an exclamation of astonishment brought Ned tohis side.
"There's something funny about this," Frank said, as Ned bent over hisshoulder. "That stuff is not oil, and I'd like to know how it got inhere."
"What does it look like?" asked Ned.
"I can't say," was the hesitating reply.
Ned took the microscope and looked at the object to which hisattention had been called.
"Rubber!" he said, in a moment.
"Rubber!" repeated Frank. "How could rubber be in the waste in thatshape?"
"All the same," Ned replied, "this is some rubber composition, and ithas been wiped into the waste. Now, what could any person want withrubber here?"
"It is used quite a lot around electric apparatus," suggested FrankShaw.
"But not in this form," Ned replied.
Then, remembering certain smooth blurs on the polished machinery hehad recently examined, he took the microscope and made anotherexamination of the spots. Presently he called Frank to his side.
"Look through the glass," he said, handing the instrument to Frank,"and tell me what you see."
"Rubber!" cried the boy, after a short examination. "There are a fewtraces here of the same rubber composition I found on the waste. Canyou tell me what it means?"
"Quite simple," Ned replied, as the boys gathered about him. "The useof rubber composition by men engaged in nefarious undertakings datesback to the time of the utilization of the whorls and lines of thehuman fingers as aids in the detection of crime."
"I guess I know what you are going to say," cried Frank.
"
When the thumb- and finger-print experts got busy with theirphotographs and their enlarged reproductions, the criminals beganstudying on methods to offset this dangerous aid to detective work."
"I knew it," cried Frank.
"And so," Ned went on, "they conceived the idea of filling the lineson the fingers and hands and making them perfectly smooth. This isrubber paint," he went on. "The man who was hidden in here when wecame in did not care to leave any finger marks behind him."
"But he did leave smooth blurs on the machines where his fingerstouched them!" said Jack.
"Certainly, and so pointed out the location of his efforts. Still, Ido not think he meditated disabling the Sea Lion. It is more probablethat he believed Lieutenant Scott to be the expert in charge of theboat and sought to kill or disable him."
"See where the chump wiped his hands on waste," Jimmie cried.
Ned now made a still closer inspection of the room and was rewardedfor his thoroughness by discovering a tiny pool of the rubbercomposition on the floor, close to the giant iron frame of the bigdynamo. Looking at the pool through his glass he discovered bits ofwool mixed with it. He put up his glass with a smile.
"We ought to be able to find this fellow now," he said, "if we getbusy before he has time to change his clothes."
"Got him, have you?" asked Jack.
"I think I could pick him out of a thousand provided he is captured inthe clothes he wore while here. His hand trembled while he was puttingthe rubber composition on his fingers and some of it dropped on hisclothing and dripped off to the floor.
"There are shreds of blue wool in this composition on the floor--soyou see he wore a blue woolen garment--probably a coat or pair oftrousers. And, see here, the fellow lost all caution when he boundedout of the submarine, after extinguishing the lights, on my entrance.
"He had already wiped the rubber off his hands on the waste, and sohis finger marks showed on the steel railing of the staircase. I'lljust take a photo of them."
When this was accomplished, Ned and Jimmie drew the Sea Lion's boat tothe edge of the float and launched it. Then, leaving Frank and Jack incharge of the submarine, with instructions to keep a close watch forsuspicious characters, they turned the prow of the rowboat towardSouth Vallejo. The distance to the wharf was not great. In fact, theintruder seemed to have cleared it in a minute, either in a boat,which was improbable, or by swimming.
The Sea Lion lay off the United States Navy Yard, on the west of MareIsland, in the straits of the same name. The nearest landing place onthe mainland, therefore, was South Vallejo.
It was after 8 o'clock when the boys reached the main street of thetown and encountered a policeman in uniform. Ned at once asked for theoffice of the Coroner of Salano County.
"What's doing?" asked the policeman.
"I have business with him," Ned replied, not caring to create asensation by reciting there in the street the details of what hadtaken place.
"Well," replied the policeman, "if you're so mighty close-mouthedregarding your business with the Coroner, you may find him yourself."
"All right," Ned replied. "I'll go to police headquarters. Perhaps thenight desk man won't be so fresh."
"Say," growled the policeman, "you needn't get gay. I know my duty.So, if you don't mind, I'll take you to headquarters, saving you thetrouble of asking for the place."
"I refuse to go with you," Ned replied.
"Oh, well," announced the other, "I'll take you along, just the same.I'm used to kids of your stamp. You're both under arrest, so you'dbetter come along without making any trouble."
As he spoke the policeman seized both boys roughly.
CHAPTER V
TWO WOLVES IN A PEN