# A Silent Witness/Chapter 7
### CHAPTER VII
#### AN UNSEEN ENEMY

FROM my late principal's house we walked away quickly down the lamplit street, all, I think, dimly amused at the circumstances of our departure.
"Is Batson always like that?" Thorndyke asked.
"Always," I replied. "Hurry and bustle are his normal states."
"Dear, dear," commented Thorndyke, "what a terrible amount of time he must waste. Of course, one can understand now how that cremation muddle came about. Your incurable hustler is always thinking of the things he has got to do next instead of the thing that he is doing at the moment. By the way, Jardine, I am taking it for granted that you would like to inspect these premises. It is not essential. Jervis and I had a preliminary look round last night, and I daresay we picked up most of the facts that are likely to be of importance if we should be going farther into the matter."
"I think it would be as well for me to take a look at the place and show you exactly where and how the affair happened."
"I think so too," said Thorndyke. "It was all pretty evident, but you might be able to show us something that we had overlooked. Here we are. I wonder if Mr. Gill is on the premises—supposing him still to frequent them."
He looked up and down the street, and, taking a key from his pocket, inserted it into the lock.
"Why, how on earth did you get the key?" I asked.
Thorndyke looked at me slyly.
"We keep a tame mechanic," said he, as he turned the key and opened the wicket.
"Yes, but how did he get the pattern of the lock?" I asked.
Thorndyke laughed softly. "It is only a simple trade lock. The fact is, Jardine, that in our branch of practice we have occasionally to take some rather irregular proceedings. For instance, I usually carry a small set of picklocks—fortunately for you. That is how I got in last night. Then I never go abroad without a little box of moulding wax; a most invaluable material, Jardine, for collecting certain kinds of evidence. Well, with a slip of wood and a bit of wax I was able to furnish my man with the necessary data for filing up a blank key. One doesn't want to be seen using a picklock. Now, can you show us the way?"
He flashed a pocket electric lamp on the ground, and we advanced over the rough cobbles until we reached a door at the side.
"This is where I went in," said I. "It opens into a sort of corridor, and at the end is a door opening on some steps that lead down to the passage below."
Thorndyke tried the handle of the door and pushed, but it was evidently locked or bolted.
"I left this door unlocked last night," said he; "so it is clear that someone has been here since. I hardly expected that. I thought our friend would have cleared off for good. But it is possible that Gill had nothing to do with the attempt. The premises may have been used by someone who happened to know that they were unoccupied. It would have been quite easy for such a person to gain admittance; as you see."
While speaking, he had produced from his pocket a little bunch of skeleton keys, with one of which he now quietly unlocked the door.
"These builders' locks," said he, "are merely symbolic of security. You are not expected to unfasten them without authority, but you can if you like and happen to have a bit of stiff wire."
We entered the corridor, and, as we proceeded, looked into the rooms that opened out of it. One of them was meagerly furnished as an office, but the thick layer of dust on the desk and stools showed clearly that it had been long disused; the other rooms were empty and desolate, and showed no trace of use or occupation.
"The worthy Gill," said Jervis, "seems to have been able, like Diogenes, to get on with a very modest outfit."
"Yes," agreed Thorndyke, "it is a little difficult to guess what his occupation is. The place looks as if it had never been used at all. Shall I go first?"
He halted for a moment, passing the light of his lamp over the massive door at the head of the steps, and then began to descend. It was certainly a horrible and repulsive place, especially to my eyes, with the recollection of my late experience fresh in my mind. The rough brick walls, covered with the crumbling remains of old whitewash, the black masses of cobwebs that drooped like funereal stalactites from the ceiling, the fungi that sprouted in corners, and the snail-tracks that glistened in the lamplight on the stone floor, all contributed to a vault-like sepulchral effect that was most unpleasantly suggestive of what might have been and very nearly had been.
My late prison was easily distinguished by the two holes in the door. We looked in; but that cellar was completely empty save for a few chips of wood and a pinch or two of sawdust; memorials of my sojourn in the lethal chamber at which I could hardly look without a shudder. Then we passed on to the next cellar—the one adjoining my prison—and this was an object of no little curiosity to me. Here, while I was securely bolted into my cell, that unknown villain had, deliberately and in cold blood, made all the arrangements for my murder; arrangements which he little suspected that I should survive to look upon.
Thorndyke, too, was interested. He stood at the open door, looking in as if considering the positions of various objects. As in fact he was.
"Someone has been here since last night, Jervis," said he.
"Yes," agreed Jervis. "That gas bottle has been taken down from the opening. You see, Jardine," he continued, "he had stood that big packing-case up on end and laid the gas bottle along the top, with its nozzle just opposite the hole. Two other bottles were standing upright with their nozzles upwards."
"I understand," said Thorndyke, "that you heard three bottles only turned on?"
"Yes," I answered; "there was the one opposite the hole and two others."
"I ask," Thorndyke said, "because there are, as you see, seven other bottles, lying by the wall. Those are all empty. We tried them when we came here last night."
"I know nothing about those others," said I. "The three bottles that I have mentioned I heard distinctly, and after he had turned on the third, the man went out of the cellar and closed up the door."
"Then," said Thorndyke, "the other seven were presumably used for some other—and let us hope, more legitimate—purpose. I wonder why our friend has been at the trouble of moving the cylinders."
"Perhaps," suggested Jervis, "he thought that the arrangement might be a little too illuminating for the police, if they should happen to pay a visit to the place. He may not be aware that the apparatus had already been inspected in situ by us. Or, again, the cylinders may have been moved by someone else. We are assuming that he is a lawful occupant of the premises; but he may be a mere secret intruder like ourselves, who has discovered that the place is more or less unoccupied and has made use of the premises and plant for his own benevolent purposes."
"Yes," agreed Thorndyke, "that is perfectly true. But we can put the matter to the test, at least negatively. If the cylinders have been moved by an innocent stranger they will bear the prints of hands."
"But why shouldn't the man himself leave the prints of his hands on the cylinders?" I asked.
"Because, my dear Jardine, he is too knowing a bird. Jervis and I went carefully over the cylinders last night in the hope of getting a few finger-prints to submit to Scotland Yard; but not a vestige could we find. Our friend had seen to that. We assumed that he had operated in gloves and your description of him confirmed our assumption. Which, in its way, is an interesting fact, for a man who is knowing enough to take these precautions has probably had some previous experience of crime, or, at least, has some acquaintance with the ways of criminals. The suggestion, in fact, is that, although this is not an ordinary professional crime, the perpetrator may be a professional criminal. And the further suggestion is, of course, that of very deliberate premeditation."
While he had been speaking he had produced from his pocket a small, flattened bottle fitted with a metal cap and filled with a yellowish powder. Removing the cap and uncovering a perforated inner cap, like that of an iodoform dredger, he proceeded to shake a cloud of the light powder over the three upper cylinders, jarring them with his foot to make the powder spread. Then he blew sharply on them, one after the other, when the powder disappeared from their surfaces, leaving visible one or two shapeless whitened smears but never a trace of a finger-print or even the shape of a hand.
Thorndyke rose and slipped the bottle back in his pocket.
"Apparently," said he, "the cylinders were moved by our unknown friend, with the same careful precautions as on the first occasion. A wary gentleman, this, Jervis. He'll give us a run for our money, at any rate."
"Yes," agreed Jervis; "he doesn't mean to give himself away. He preserves his incognito most punctiliously. I'll say that for him."
"And meanwhile," said Thorndyke, "we had better proceed with our measures for drawing him out of this modest retirement. I want you, Jardine, to look round this cellar and tell us if any of the things that you see in it reminds you of anything that has happened to you, or suggests any thought or reflection."
I looked round, I am afraid rather vacantly. A more unsuggestive collection of objects I have never looked upon.
"There are the gas cylinders," I said, feebly; "but I have told you about them. I don't see anything else excepting a few oddments of rubbish."
"Then take a good look at the rubbish," said he. "Remember that it may be necessary at some future time for you to recall exactly what this cellar was like, and what it contained. You may even have to make a sworn statement. So cast your eye round and tell us what you see."
I did so, wondering inwardly what the deuce I was expected to see and what might be the importance of my seeing it.
"I see," said I, "a mouldy-looking cellar about fifteen feet by twelve, with very bad brick walls, a plaster ceiling in an advanced stage of decay, and a concrete floor. In the left hand wall is a hole about six inches square opening into the adjoining cellar. The contents are ten gas cylinders, all apparently empty, a key or spanner which seems to have been used to turn the cocks, a large packing-case, which, to judge by its shape, seems to have contained gas cylinders---"
"The word 'large,'" interrupted Thorndyke, "is not a particularly exact one."
"Well, then, a packing-case about seven feet long by two and a half feet wide and deep."
"That's better," said Thorndyke. "Always give your dimensions in quantitative terms if possible. Go on."
"There are a couple of waterproof sheets," said I. "I don't see quite what they can have been used for."
"Never mind their use," said Thorndyke. "Note the fact that they are here."
"I have," said I; "and that seems to complete the list with the exception of the straw in which I suppose the gas cylinders were packed. There is a large quantity of that, but not more than would seem necessary for the purpose. And that seems to complete the inventory, and, I may say, that none of these things conveys any suggestion whatever to my mind."
"Probably not," said Thorndyke, "and it is quite possible that none of these things has any particular significance at all. But as they are the only facts offered us, we must make the best of them. There is one other cellar that we have not yet looked into, I think."
We came out, and, walking along the passage, came to another door which stood slightly ajar. Thorndyke opened it, and, throwing in the light of his lamp, revealed a considerable stack of long iron gas bottles, and one or two packing-cases similar to the one I had already seen.
"I presume," said he, "that these are full cylinders; the store from which our friend got his supply, but we may as well make sure."
He ran back into the adjoining cellar, and returned with the spanner, with which he proceeded to turn the cock of one of the topmost cylinders; upon which a loud hiss and a thin, snowy cloud showed that his surmise was correct.
He had just closed the cock and stepped out into the passage to take back the spanner, when I saw him stop suddenly as if listening. And then he sniffed once or twice.
"What is it?" asked Jervis; but Thorndyke, without replying, ran quickly along the passage and up the steps, and I heard him trying the door at the top.
"Bring up one of the empty cylinders," he said quietly. "They have bolted us in and apparently set fire to the place."
We did not require much urging to act quickly. Picking up one of the long, ponderous iron cylinders, we ran with it along the passage towards the light of Thorndyke's lamp. As we ascended the steps I became plainly aware of the smell of burning wood and of a crackling sound, faintly audible through the massive door.
"There is only one bolt," said Thorndyke; "I noticed it as we came in. I will throw my light on the part of the door where it is fixed, and you two must batter on that spot with the cylinder."
The door was, as I have said, a massive one, but it would have been a massive door indeed that could have withstood the blows of that ponderous iron cylinder, wielded by two strong men whose lives depended on their efforts. At the very first crash of the battering-ram, a tiny chink opened and at each thundering blow, the building shook. Furiously we pounded at the thick, plank-built door, and slowly the chink widened as the screws of the bolt tore out of the woodwork. And as the chink opened, a thin reek of pungent smoke filtered in, and the cold light of Thorndyke's lantern became contrasted with a red glare from without. And then suddenly, the door, under the heavy battering, burst from its fastenings and swung open. A blinding, choking cloud of smoke and sparks rolled in upon us, through which we could see in the corridor outside a pile of straw and crates and broken packing-cases, blazing and cracking furiously. It looked as if we were cut off beyond all hope.
Jervis and I had dropped the now useless cylinder and were gazing in horror at the blazing mass that filled the corridor and cut off our only means of escape, when we were recalled by the voice of Thorndyke, speaking in his usual quiet and precise manner.
"We must get the full cylinders up as quickly as possible," said he; and, running down the steps he made straight for the end cellar, whither we followed him. Picking up one of the cylinders, we carried it quickly to the top of the steps. "Lay it down," said Thorndyke, "and fetch another."
Jervis and I ran back to the cellar, and taking up another cylinder, brought it along the passage. As we were ascending the steps, there suddenly arose a loud, penetrating hiss, and as we reached the top, we saw Thorndyke disengaging the spanner from the cock of the cylinder out of which a jet of liquid was issuing, mingled with a dense, snowy cloud.
An instantaneous glance, as we laid down the fresh cylinder, reassured me very considerably. The icy, volatile liquid and the falling cloud of intensely cold carbonic acid snow had produced an immediate effect; as was evident in a blackened, smouldering patch in the midst of the blazing mass. With reviving hope I followed Jervis once more down the steps and along the passage to the end cellar, from which we brought forth a third cylinder.
By this time the passage was so filled with smoke that it was difficult either to see or to breathe, and the bright light that had at first poured in through the open doorway had already pulled down so far that Thorndyke's figure, framed in the opening, loomed dim and shadowy amidst the smoke and against the dusky red background. We found him, when we reached the top of the steps, holding the great gas bottle and directing the stream of snow and liquid on to those parts of the wood and straw from which flames still issued.
"It will be all right," he said in his calm, unemotional way; "the fire had not really got an effective start. The straw made a great show, but that is nearly all burnt now, and all this carbonic acid gas will soon smother the burning wood. But we must be careful that it doesn't smother us too. The steps will be the safest place for the present."
He opened the cock of the new cylinder and, having placed it so that it played on the most refractory part of the burning mass, backed to the steps where Jervis and I stood looking through the doorway. The fire was, as he has said, rapidly dying down. The volumes of gas produced by the evaporation of the liquid and the melting snow, cut off the supply of air so that, in place of the flames that had, at first, looked so alarming, only a dense reek of smoke arose.
"Now," said Thorndyke, after we had waited on the steps a couple of minutes more, "I think we might make a sortie and put an end to it. If we can get the smouldering stuff off that wooden floor down on to the stone, the danger will be over."
He led the way cautiously into the corridor, and, once more bringing his electric lamp into requisition, began to kick the smouldering cases and crates and the blackened masses of straw down the steps on to the stone floor of the passage, whither we followed them and scattered them with our feet until they were completely safe from any chance of re-ignition.
"There," said Jervis, giving a final kick at a small heap of smoking straw, "I should think that ought to do. There's no fear of that stuff lighting up again. And, if I may venture to make the remark, the sooner we are off these premises the happier I shall be. Our friend's methods of entertaining his visitors are a trifle too strenuous for my taste. He might try dynamite next."
"Yes," I agreed; "or he might take pot shots at us with a revolver from some dark corner."
"It is much more likely," said Thorndyke, "that he has cleared off in anticipation of the alarm of fire. Still, it is undeniable that we shall be safer outside. Shall I go first and show you a light?"
He piloted us along the corridor and up the cobbled yard, putting away his lamp as he unlocked the wicket. There was no sign of anyone about the premises nor, when we had passed out of the gate, was there anyone in sight in the street. I looked about, expecting to see some sign of the fire; but there was no smoke visible, and only a slight smell of burning wood. The smoke must have drifted out at the back.
"Well," Thorndyke remarked, "it has been quite an exciting little episode. And a highly satisfactory finish, as things turned out; though it might easily have been very much the reverse. But for the fortunate chance of those gas-bottles being available, I don't think we should be alive at this moment."
"No," agreed Jervis. "We should be in much the same condition by this time as Batson's late patient, Mr. Maddock, or at least, well on our way to that disembodied state. However, all's well that ends well. Are you coming our way, Jardine?"
"I will walk a little way with you," said I. "Then I must go back to Batson to settle up and fetch my traps."
I walked with them to Oxford Street and we discussed our late adventure as we went.
"It was a pretty strong hint to clear out, wasn't it?" Jervis remarked.
"Yes," replied Thorndyke; "it didn't leave us much option. But the affair can't be left at this. I shall have a watch set on those premises, and I shall make some more particular inquiries about Mr. Gill. By the way, Jardine, I haven't your address. I'd better have it in case I want to communicate with you; and you'd better have my card in case anything turns up which you think I ought to know."
We accordingly exchanged cards, and, as we had now reached the corner of Oxford Street, I wished my friends adieu and thoughtfully retraced my steps to Jacob Street.