He wondered how the mess plate had happened to be in the stateroom, anyway. Sherlock n.o.body Holmes again! But the crew, as well as the troops, carried their supper wherever they pleased to eat it. So there was nothing so strange about that. If there had been, why, Uncle Sam"s all-seeing eye would not have missed it.
He fell to thinking of Bridgeboro again. And he thought of Adolf Schmitt and----
A phrase from one of those letters ran through his mind--_It"s the same idea as a periscope_.
For a moment Tom Slade felt just as so often he had felt when he had found an indistinct footprint along a woodland trail. _What_ was the same idea as a periscope? What was a periscope, anyway?
Why, a thing on a submarine by means of which you could look two ways at once--you could look up through the ocean and across the ocean--all with one look.
He wondered whether Mr. Conne had noticed that rather puzzling phrase and whether the people on this ship had seen that letter. Mr. Conne had seemed to think that one the least important of the lot. Perhaps he had just told the ship"s people to look out for spies. And they would do that anyway. The names of uniformed spies in the army cantonments--names in black and white--that was the important thing--the big discovery.
But Tom Slade was only a humble Sherlock n.o.body Holmes and he couldn"t get that phrase out of his head.
_It"s the same idea as a periscope._
A periscope is a kind of a--a kind of a----
Tom"s brow was knit, just as when he used carefully and anxiously to move the gra.s.s away from an all but obliterated footprint, and his eyes were half closed and keen.
"I know what it is," he said to himself, suddenly. "It means how light can be pa.s.sed through a room even while the room is dark all the time--kind of reflected--and you wouldn"t have to use any match."
He stood still, almost frightened at his own conclusion. The clean, shiny mess plate and the phrase out of that letter seemed to fit together like the sections of a picture puzzle. The black spot and the match-end (if there was any match-end) meant just nothing at all. The dim light out in the pa.s.sageway down below hardly reached the dark staterooms, but----
He could not remember just how it was down there, but he knew that in the staterooms where the gla.s.s ports were locked (and that was the case with all of the crews" quarters below) air was admitted by a slightly opened panel transom over the door.
What should he do? Go and tell an officer about his discovery? If it _were_ a discovery that would be all very well. But after all, this was only a--a kind of a _deduction_. And they might laugh at him. He had always stood in awe of the officers and since last night he was mortally afraid of them. If he told any of the soldiers or even the steward they would only jolly him. He did not know exactly what he had better do.
He made up his mind that he would go down through the pa.s.sageway where those under engineers and electricians slept and see how it looked down there. He had been through there many times, but he thought that perhaps he would notice some thing now which would help to prove his theory and then perhaps they would listen to the captain"s mess boy if he could muster the courage to speak.
He had just left the rail when he saw, some distance to starboard as it seemed, and well forward of the ship, an infinitesimal bluish brown spark. How he happened to notice it he did not know. "Once a scout, always a scout," perhaps. In any event, it was only by fixing his eyes intently upon it that he could keep it in sight. And even so, he lost it after a few seconds. He tried to find it again, but quite in vain. It had been about as conspicuous as a snowflake would have been in a gla.s.s of milk.
"Huh, if there"s anyone on this ship can see _that_, he must be a peach.
Maybe up in the rigging you can see it better, though. If it"s on the destroyer, she"s quite a ways ahead of us----"
He squinted his eyes and, seeing a number of imaginary lights, decided that perhaps the other had been imaginary too. He crossed the saloon, went down the companionway and through the second cla.s.s cabin dining-room where the soldiers hailed him pleasantly, and, pa.s.sing the stokers" washroom, tiptoed along the dim, narrow pa.s.sageway.
CHAPTER X
HE GOES BELOW AND GROPES IN THE DARK
There were half a dozen or more staterooms along this pa.s.sage. At the end of it was the steep, greasy flight of iron steps leading down into the engine-rooms. Here, also, was a huge box with a hinged lid, filled with cotton waste. It was customary for one going down here to take a handful of this waste to protect his hands from the oily rail, and also on coming up to wipe his hands with a fresh lot. The very atmosphere of a ship"s engine-room is oily. Here, also, were several fire-buckets in a rack.
Along the side of the pa.s.sage opposite the staterooms were electric bulbs at intervals, but only two of them were burning--just enough to light one through the narrow pa.s.sage. Above each closed door was a solid wooden transom, hinged at its lower side and opened at an angle into the room.
Tom moved quickly and very quietly, for he feared to be caught loitering here. He saw at once that only one of these staterooms could possibly be used for any such criminal purpose as he suspected, and that was the one with a light directly opposite it in the pa.s.sage, for the other light was beyond the staterooms.
For a few seconds he stood listening to the slow, monotonous sound of the machinery just below him. The vibration was very p.r.o.nounced here; the floor thumped with the pulsations of the mighty engines. And Tom"s heart was thumping too.
Within the staterooms all was dark and quiet. He knew the under engineers turned in early. Not the faintest flicker was to be seen through any of those transoms. He had been mistaken, he thought; had jumped at a crazy notion. And he half turned to go up again.
But instead he listened at the companionway, then tiptoed stealthily along the pa.s.sage and looked over the oily iron rail, down, down into the depths of the great, dim, oil-smelling s.p.a.ce with its iron galleries and the mammoth steel arms, moving back and forth, back and forth, far down there upon the grated floor. A tiny figure in a jumper went down from one of the lower galleries, paused to look at a big dial, then crossed the floor and disappeared, making never a sound. No other living thing was in sight--unless those mighty steel arms, ever meeting and parting might be said to be living. To come up from down there would mean the ascent of three iron stairways.
Tom withdrew into the pa.s.sage and quietly lifting one of the fire-buckets from the rack, tiptoed with it to the door which was directly opposite the pa.s.sageway.
Then he paused again. He could open that door, he knew, for no keys or bolts were allowed on any stateroom door. He could surprise the occupant, whom he would find in darkness. If his suspicion was correct (and he was beginning now to fear that it was not) there would be no actual proof of anything inside of that dark little room, save only just what the authorities had already found--an apparently innocent mess plate. The criminal act would consist of simply holding a shiny plate in a certain position. The moment a sound was heard outside the plate could be laid down. And who would be the wiser?
Tom"s heart was thumping in his breast, his eyes anxiously scanning one end of the pa.s.sage, then the other.
Not a sound--no sign of anyone.
Tom Slade had been a scout and notwithstanding his suspense and almost panicky apprehension, he was not going to act impulsively or thoughtlessly. He knew that if he could only present a convincing case to his superiors, they would forgive him his presumption. If he made a bungle it might go hard with him. Anyway, he could not, or would not, turn back now.
In truth, he did not believe that anything at all was going to happen.
The stateroom was so dark and so still that all his fine ideas and deductions, which had seemed so striking and plausible up on the lonesome, wind-swept deck, began to fade away.
But there would be no harm in one little test, and no one would be the wiser. He tried to picture in his mind"s eye the interior of that little stateroom. If it were like his own, then the mirror was on the other side of the pa.s.sage wall, that is, on the opposite side of the stateroom from the port hole. If one looked into the mirror he would see the port hole. All of the smaller rooms below decks which he had seen were arranged in the same way.
Therefore, thought Tom, if one should hold a shiny mess plate, for instance, up near the transom, so as to catch the light from without, he could throw it down into the mirror, which would reflect not only the glare but the brilliant image of the bulb as well. From out on the ocean that reflected light would be very clear.
All of which, thought Tom dubiously, was a very pretty theory, but----
Without making a sound he placed the inverted bucket on the floor and listened. He put one foot on it and listened again. Then he stood upon it, his heart pounding like a triphammer.
Not a sound.
Probably the tired occupant of the room was fast asleep--sleeping the peaceful sleep of the innocent.
Tom knew that if his mind"s eye picture of the room"s arrangement were correct, the metal reflector would be of no avail unless tilted at a slight angle from the horizontal, right inside the transom.
For a moment he stood upon the bucket, not daring to budge. He could hear his own breathing, and far away the steady, dull thud of the tireless machinery. Something creaked in the pa.s.sage, and he turned cold. He did not stir a muscle.
Only some superficial crevice or crack somewhere--some loose panel or worn hinge responding to the onslaught of a giant wave without---- Nothing----
He turned his head and looked down the pa.s.sage, clenching his fists in momentary fright, as if he feared the bending of his neck might be heard.
No one. Not a sound.
He tried to look through the transom but his eyes were not high enough.
For another second he paused. Then he reached through the transom and moved his hand about in the silence and darkness. He heard the cracking again and waited, trembling, though he knew it was nothing.
Then he groped about with his hand again.