Brock's lungs ached queerly. Must have gotten a whiff of that gunk of mine, he thought; that was a fool thing to do. But there couldn't have been enough to do any real harm. He kept on. The ache got worse; there was a strange suffocating sensation. This is serious, he thought. I'd better see a doctor after I deliver Halperin's message to Sugden. He kept on.
His lungs seemed to be on fire. Hurry—hurry—Dumville's an M.D.; maybe he could fix me up. Brock couldn't breathe. He wanted water—not, oddly, in his throat, but in his lungs. The cool depths of the big tank and the end of the semicircle were below him. This tank held the sharks; the other big tank, for groupers and other giants of the bass tribe, was across from it.
His lungs burned agonizingly. He tried to call out, but only made a faint croaking noise. The tangle of pipes seemed to whirl around him. The sound of running water became a roar. He swayed, missed a snatch at the nearest reserve tank, and pitched into the shark tank.
There was water in his eyes, in his ears, everywhere. The burning in his lungs was lessening, and in place of it came a cold feeling throughout his chest. The bottom came up and bumped him softly. He righted himself. That was wrong; he should have floated. Then the reason came to him; his lungs were full of water, so that his specific gravity was one point something. He wondered for a confused minute if he was already drowned. He didn't feel drowned, only very wet and very cold inside. In any event he'd better get out of here quickly. He kicked himself to the surface, reached up and grabbed the catwalk, and tried to blow the water out of his lungs. It came, slowly, squirting out of his mouth and nostrils. He tried inhaling some air. He thought he was getting somewhere when the burning sensation returned. In spite of himself he ducked and inhaled water. Then he felt all right.
Everything seemed topsy-turvy. Then he remembered the liquid he'd prepared for the alligator; it must have worked on him! His lungs were functioning as gills. He couldn't quite believe it yet. Experimenting on an alligator is one thing; turning yourself into a fish is another—comic-section stuff. But there it was. If he'd been going to drown he'd have done so by now. He tried a few experimental breaths under water. It was amazingly hard work. You put on the pressure, and your lungs slowly contracted, like a pneumatic tire with a leak. In half a minute or so you were ready to inhale again. The reason was the density of water compared with that of air, of course. But it seemed to work. He released the catwalk and sank to the bottom again. He looked around him. The tank seemed smaller than it should be; that was the effect of the index of refraction of water, no doubt. He walked toward one side, which seemed to recede as he approached it. A fat nurse-shark lying on the bottom waved its tail and slid forward out of his way.
The other two nurse-sharks were lying indifferently on the bottom across the tank. These brutes were sluggish and utterly harmless. The two sand-sharks, the four-footer and the five-footer, had ceased their interminable cruising and had backed into far corners. Their mouths opened and closed slowly, showing their formidable teeth. Their little yellow eyes seemed to say to Brock, "Don't start anything you can't finish, buddy." Brock had no intention of starting anything. He'd had a healthy respect for the species since one of them had bitten him in the gluteus maximus while he was hauling it into a boat.
He looked up. It was like looking up at a wrinkled mirror, with a large circular hole in it directly over his head. Through the hole he could see the reserve tanks, the pipes—everything that he could have seen by sticking his head out of water. But the view was distorted and compressed around the edges, like a photograph taken with a wide-angle lens. One of the aquarium's cats peered down inscrutably at him from the catwalk. Beyond the circle on all sides the water-surface was a mirror that rippled and shivered. Over the two sand-sharks were their reflections upside down.
He turned his attention to the glass front of the tank. That reflected things too, as the lamps suspended over the water made the inside brighter than the outside. By putting his head close to the glass he could see the Aquarium's interior concourse. Only he couldn't see much of it for the crowd in front of the tank. They were staring at him; in the dim light they seemed all eyeballs. Now and then their heads moved and their mouths moved, but Brock got only a faint buzz.
This was all very interesting, Brock thought, but what was he to do? He couldn't stay in the tank indefinitely. For one thing, the coldness in his chest was uncomfortable. And God only knew what terrible physiological effect the gas might have had on him. And this breathing water was hard work, complicated by the fact that unless watched carefully his glottis would snap shut, stopping his breath altogether. It was like learning to keep your eyes open under water. He was fortunate in having fallen into a tank of salt water; fresh water is definitely injurious to lung-tissue, and so it might have been even to the modified tissue in his lungs.
He sat down crosslegged on the bottom. Behind him the larger sand-shark had resumed its shuttling, keeping well away from him and halting suspiciously every time he moved. Two remoras, attached to the shark by the sucking-disks on top of their heads, trailed limply from it. There were six of these original hitch-hikers in the tank. He peered at the glass front. He took off his glasses experimentally, and found that he could see better without them—a consequence of the different optical properties of water and air. Most of the Aquarium's visitors were now crowded in front of that tank, to watch a youngish man in a black rubber apron, a striped shirt, and the pants of a gray flannel suit sit on the bottom of a tank full of sharks and wonder how in Hell he was going to get out of this predicament.
Overhead, there was no sign of anybody. Evidently nobody had heard him fall in. But soon one of the small staff would notice the crowd in front of the tank and investigate. Meanwhile he'd better see just what he could do in this bizarre environment. He tried to speak. But his vocal cords, tuned to operate in a negligibly dense medium, refused to flutter fast enough to emit an audible sound. Well, maybe he could come to the surface long enough to speak and duck under again. He rose to the top and tried it. But he had trouble getting his watersoaked breathing and speaking apparatus dry enough to use for this purpose. All he produced were gurgling noises. And while the air no longer burned his lungs on immediate contact, keeping his head out soon gave him a dizzy, suffocating feeling. He finally gave up and sank to the bottom again.
He shivered with the cold, although the water was at 65° Fahrenheit. He'd better move around to warm up. The apron hampered him, and he tried to untie the knot in back. But the water had swollen the cords so that the knot wouldn't budge. He finally wriggled out of it, rolled it up, stuck his arm out of water, and tossed the apron onto the catwalk. He thought of removing his shoes too, but remembered the sand-shark's teeth.
Then he did a bit of leisurely swimming, round and round like the sand-sharks. They also went round and round, trying to keep the width of the tank between him and them. The motion warmed him, but he tired surprisingly soon. Evidently the rapid metabolism of a mammal took about all the oxygen that his improvised gills could supply, and they wouldn't carry much overload. He reduced his swimming to an imitation of a seal's, legs trailing and hands flapping at his sides. The crowd, as he passed the front of the tank, was thicker than ever. A little man with a nose that swerved to starboard watched him with peculiar intentness.
A jarring sound came through the water, and presently figures, grotesquely shortened, appeared at the edge of the circle of transparency overhead. They grew rapidly taller, and he recognized Sugden, Dumville, Sam Baritz, and a couple of other members of the staff. They clustered on the catwalk, and their excited voices came to him muffled but intelligible. They knew what had happened to him, all right. He tried by sign-language to explain his predicament. They evidently thought he was in a convulsion, for Sugden barked, "Get him out!" Baritz's thick forearm shot down into the water to seize his wrist. But he wrenched loose before they had him clear of the surface, and dove for the bottom.