The lighted portholes winked out one by one, as if he were passing beyond the wall of the cavern into a subterranean sea, and abruptly we toppled forward, off the edge of the shipyard floor, descending in a rush of bubbles, swept along in a current that bore us away eastward, as St. Ives had promised. The only illumination came from our own craft now, but I thanked God for it, underwater darkness filling me with a certain horror. More eels undulated past the portholes, and a school of small, white fish, and then a corpse floated past, bloated and pale, its sightless, milky eyes staring in at us for a long moment before it was swept away in a current. It was horrible, and yet I scarcely remarked it, my mind still dwelling on the submarine and the living, corpse-like man who navigated it. Where had it gone, I wondered, and why had Frosticos allowed us our freedom, if indeed he had?
The water slowly brightened roundabout us. St. Ives switched off the lamps both inside and out, so as not to waste power. If we were tethered to a ship, he pointed out, then the ship’s engines would generate abundant electricity, but we depended upon the batteries — what he had meant by dry cells—which were an unknown quantity. We discovered ourselves to be in the depths of the Thames itself, the water murky with silt and river filth. How far we had come in the darkness we couldn’t say. Our rate of travel was mere speculation. It had no doubt been equal to that of the river, but where in the river were we?
It wouldn’t do, St. Ives said, to surface in the Pool, or in some other part of the river busy with shipping, and run afoul of a ship’s hawser, or come rushing up from below to tear a hole in a ship’s bottom. And of course as long as we were afloat, we traveled at the whim of the current, whereas we had some hope of controlling our movements if we could find the bottom in still water. How to accomplish this feat — that was the thorny problem, although St. Ives had clearly taken it up as a challenge. We clanked into something unseen, spun slowly, and continued on our way. I let in another burst of air. Through the port I could see what must have been the remains of a wrecked coal barge slide past, and I realized that all manner of debris lay on the river bottom, most of it half buried in muck. It would have made fascinating viewing, no doubt, under different circumstances.
St. Ives allowed more water into the ballast tanks, and we sank again, settling momentarily, a cloud of mud rising around us and obscuring our sight. We found ourselves toppling forward as the river pushed against us, and it was only by flushing water out of the ballast tanks that we managed to right ourselves once more, bobbing along eastward again, careening this way and that way in a manner that was soon sickening, as if we were afloat in a laundry tub. I let in more of our precious air, which we seemed to be breathing up at a prodigious rate. Directly after that we were cast in shadow, a shadow that stayed with us for some time before passing on.
“A ship,” St. Ives said, looking upward through a port. “Out of the Pool rather late.” He took his chronometer from his pocket and peered at its face. “The tide is making, or nearly, if I’m not mistaken.”
“Yes, sir,” Hasbro put in. “Just past midday, given the moon’s activities.”
“Excellent,” St. Ives said, winking at me.
I nodded my hearty assent, although truth to tell I know little about the tides. What I cared about at that moment was for the craft to cease its constant, rollicking, drunken behavior.
“We’ll have a period of slack water soon,” St. Ives told me by way of explanation. “Enough time, I very much hope, to find our way out of the river, ideally downstream some small distance, where we’ll cause less of a sensation. Air, Jack.”
“But when the tide turns,” I said as I reached for the lever yet again, “won’t that merely propel us back upriver?” I recalled the corpse that had visited us earlier. Quite likely it would continue to navigate the same shoreline, upriver and down, at the whim of the tides and with no end to its travels until it simply fell apart or was hauled in by a dredger’s net.
“Absolutely,” St. Ives said. “It won’t matter to us, though. Don’t give it a second thought.”
“Ah?” I said, wondering at this. Certainly it seemed to matter.
“We’ll be suffocated before the tide flows again,” St. Ives assured me. “Almost without a doubt. There’s no telling how much air we’ve been blessed with, but even if the tanks were full, with three of us breathing up the surplus we’ll be dead as herring in a couple of hours. You can bank on it.”
This silenced me, I can assure you, although St. Ives hadn’t meant for it to. He was merely making a practical observation. For another half hour or more we floated and bumped and spun our way downriver, in and out of the shadows of moored or passing craft. I found that I had become unnaturally conscious of my breathing, and so I began breathing unnaturally, gasping now and then with no provocation, mimicking the wheezing of the air in the pipes. What had seemed a spacious chamber had shrunk to the size of a pickle barrel, and I fidgeted about, trying to occupy myself by peering out the ports, spotting no end of mired flotsam — a wagon wheel, a tailor’s dummy, a chest half buried in silt and enticingly bound shut with heavy rope, probably containing gold coins and Java pearls the size of goose eggs, but already disappearing behind us.
“Air, Jack.”
It seemed to me that the rush of air was labored now, as if the pressure were low. But I was distracted from that frightful thought when I became aware that we were slowing settling again to the bottom. River mud swirled up around us so that for a moment we could see nothing at all. St. Ives consulted a compass among a small array of instruments, and when the murk settled he pointed out a long, curved wooden beam, a ship’s keel perhaps, lying half exposed on the river bottom. “That’s our bearing,” he said. “Along the edge of that beam. Due north.”
He began to manipulate the motivating levers once again, carefully now, waiting for the muddy water to clear time and again to get a view of the sunken keel so that we could take another creeping step. We edged around impediments sideways, like a crab, and two or three times backed away from a cavernous sort of rocky pit. Twice we mired ourselves in weeds and had to tug ourselves free. The broken end of the keel was far out of sight behind us now, and St. Ives was navigating by compass alone, adjusting and readjusting our direction of travel, none of us speaking or moving more than was strictly necessary. How much time passed, I couldn’t say, nor could any of us guess whether we were twenty feet from shore or sixty, whether we would creep out onto dry land, or bang up against the base of a cliff and find ourselves no nearer salvation than we ever were.
Again I opened the air valve, but the flow was feeble, a tired hiss, and the air in the chamber was distressingly thick. I tried to distract myself by watching our progress, but it was too frustratingly slow, and there was little of interest to be seen in the river, which was perpetually murky now in the slack water. Hasbro, who had either been asleep or in deep meditation, said, “I beg your pardon, sir?” and I had no idea what he meant until I heard the echo of my own voice in my ears, and I realized that I had been talking out loud, like a mad man, and with no idea what I had said.