It wasn't until the mermaid turned up in his bathtub that Simon Grue seriously began to wonder what the Russians were doing on the roof next door.

The old house next door together with its spacious tarpapered roof, which held a sort of pent-shack, a cylindrical old water tank, and several chicken-wire enclosures, had always been a focus of curiosity in this region of Greenwich Village, especially to whoever happened to be renting Simon's studio, the north window-cum-skylight of which looked down upon it—if you were exceptionally tall or if, like Simon, you stood halfway up a stepladder and peered.

During the 1920's, old-timers told Simon, the house had been owned by a bootlegger, who had installed a costly pipe organ and used the water tank to store hooch. Later there had been a colony of shaven-headed Buddhist monks, who had strolled about the roof in their orange and yellow robes, meditating and eating raw vegetables. There had followed a commedia dell' arte theatrical group, a fencing salon, a school of the organ (the bootlegger's organ was always one of the prime renting points of the house), an Arabian restaurant, several art schools and silvercraft shops of course, and an Existentialist coffee house.

The last occupants had been two bony-cheeked Swedish blondes who sunbathed interminably and had built the chicken-wire enclosures to cage a large number of sinister smoke-colored dogs—Simon decided they were breeding werewolves, and one of his most successful abstractions, "Gray Hunger", had been painted to the inspiration of an eldritch howling. The dogs and their owners had departed abruptly one night in a closed van, without any of the dogs ever having been offered for sale or either of the girls having responded with anything more than a raised eyebrow to Simon's brave greetings of "Skoal!"

The Russians had taken possession about six months ago—four brothers apparently, and one sister, who never stirred from the house but could occasionally be seen peering dreamily from a window. A white card with a boldly-inked "Stulnikov-Gurevich" had been thumbtacked to the peeling green-painted front door. Lafcadio Smits, the interior decorator, told Simon that the newcomers were clearly White Russians; he could tell it by their bushy beards. Lester Phlegius maintained that they were Red Russians passing as White, and talked alarmingly of spying, sabotage and suitcase bombs.

Simon, who had the advantages of living on the spot and having been introduced to one of the brothers—Vasily—at a neighboring art gallery, came to believe that they were both Red and White and something more—solid, complete Slavs in any case, Double Dostoevsky Russians if one may be permitted the expression. They ordered vodka, caviar, and soda crackers by the case. They argued interminably (loudly in Russian, softly in English), they went on mysterious silent errands, they gloomed about on the roof, they made melancholy music with their deep harmonious voices and several large guitars. Once Simon though they even had the bootlegger's organ going, but there had been a bad storm at the time and he hadn't been sure.

They were not quite as tight-lipped as the Swedish girls. Gradually a curt front-sidewalk acquaintance developed and Simon came to know their names. There was Vasily, of course, who wore thick glasses, the most scholarly-looking of the lot and certainly the most bibulous—Simon came to think of Vasily as the Vodka Breather. Occasionally he could be glimpsed holding Erlenmayer flasks, trays of culture dishes, and other pieces of biological equipment, or absentmindedly wiping off a glass slide with his beard.

Then there was Ivan, the dourest of the four, though none of them save Vasily seemed very amiable. Simon's private names for Ivan were the Nihilist and the Bomber, since he sometimes lugged about with him a heavy globular leather case. With it and his beard—a square black one—he had more than once created a mild sensation in the narrow streets of the Village.

Next there was Mikhail, who wore a large crucifix on a silver chain around his neck and looked like a more spiritual Rasputin. However, Simon thought of him less as the Religious than as the Whistler—for his inveterate habit of whistling into his straggly beard a strange tune that obeyed no common harmonic laws. Somehow Mikhail seemed to carry a chilly breeze around with him, a perpetual cold draught, so that Simon had to check himself in order not to clutch together his coat collar whenever he heard the approach of the eerie piping.

Finally there was Lev, beardless, shorter by several inches, and certainly the most elusive of the brothers. He always moved at a scurry, frequently dipping his head, so that it was some time before Simon assured himself that he had the Stulnikov-Gurevich face. He did, unmistakably. Lev seemed to be away on trips a good deal. On his returns he was frequently accompanied by furtive but important-looking men—a different one on each occasion. There would be much bustle at such times—among other things, the shades would be drawn. Then in a few hours Lev would be off again, and his man-about-town companion too.

And of course there was the indoors-keeping sister. Several times Simon had heard one of the brothers calling "Grushenka", so he assumed that was her name. She had the Stulnikov-Gurevich face too, though on her, almost incredibly, it was strangely attractive. She never ventured on the roof but she often sat in the pent-shack. As far as Simon could make out, she always wore some dark Victorian costume—at least it had a high neck, long sleeves, and puffed shoulders. Pale-faced in the greenish gloom, she would stare for hours out of the pent-shack's single window, though never in Simon's direction. Occasionally she would part and close her lips, but not exactly as if she were speaking, at least aloud—he thought of calling her the Bubble Blower. The effect was as odd as Mikhail's whistling but not as unpleasant. In fact, Simon found himself studying Grushenka for ridiculously long periods of time. His mild obsession began to irk him and one day he decided henceforth to stay away altogether from his north window and the stepladder. As a result he saw little of the alterations the Russians began to make on the roof at this point, though he did notice that they lugged up among other things a length of large-diameter transparent plastic piping.

So much for the Russians, now for the mermaid. Late one night Simon started to fill his bathtub with cold water to soak his brushes and rags—he was working with a kind of calcimine at the time, experimenting with portable murals painted on large plaster-faced wooden panels. Heavily laden, he got back to the bathroom just in time to shut off the water—and to see a tiny fish of some sort splashing around in it.

He was not unduly surprised. Fish up to four or five inches in length were not unheard-of apparitions in the cold-water supply of the area, and this specimen looked as if it displaced no more than a teaspoon of water.

He made a lucky grab and the next moment he was holding in his firmly clenched right hand the bottom half of a slim wriggling creature hardly two inches long—and now Simon was surprised indeed.

To begin with, it was not greenish white nor any common fish color, but palely-pinkish, flesh-colored in fact. And it didn't seem so much a fish as a tadpole—at least its visible half had a slightly oversize head shaped like a bullet that has mushroomed a little, and two tiny writhing arms or appendages of some sort—and it felt as if it had rather large hips for a fish or even a tadpole. Equip a two-months human embryo with a finny tail, give it in addition a precocious feminine sexiness, and you'd get something of the same effect.

But all that was nothing. The trouble was that it had a face—a tiny face, of course, and rather goggly-ghostly like a planarian's, but a face nevertheless, a human-looking face, and also (here was the real trouble) a face that bore a grotesque but striking resemblance to that of Grushenka Stulnikov-Gurevich.

Simon's fingers tightened convulsively. Simultaneously the slippery creature gave a desperate wriggle. It shot into the air in a high curve and fell into the scant inch of space between the bathtub and the wall.

The next half hour was hectic in a groveling sort of way. Retrieving anything from behind Simon's ancient claw-footed bathtub was a most difficult feat. There was barely space to get an arm under it and at one point the warping of the floor boards prevented even that. Besides, there was the host of dust-shrouded objects it had previously been too much trouble to tease out—an accumulation of decades. At first Simon tried to guide himself by the faint flopping noises along the hidden base of the wall, but these soon ceased.

Being on your knees and your chest with an ear against the floor and an arm strainingly outstretched is probably not the best position to assume while weird trains of thought go hooting through your head, but sometimes it has to happen that way. First came a remembered piece of neighborhood lore that supported the possibility of a connection between the house next door and the tiny pink aquatic creature now suffering minute agonies behind the bathtub. No one knew what ancient and probably larceny-minded amateur plumber was responsible, but the old-timers assured Simon there was a link between the water supply of the Russians' house with its aerial cistern and that of the building containing Simon's studio and several smaller apartments; at any rate they maintained that there had been a time during the period when the bootlegger was storing hooch in the water tank that several neighborhood cold-water taps were dispensing a weak but nonetheless authoritative mixture of bourbon and branch water.

So, thought Simon as he groped and strained, if the Russians were somehow responsible for this weird fishlet, there was no insuperable difficulty in understanding how it might have gotten here.

But that was the least of Simon's preoccupations. He scrabbled wildly and unsuccessfully for several minutes, and then realizing he would never get anywhere in this unsystematic manner, he began to remove the accumulated debris piece by piece: dark cracked ends of soap, washrags dried out in tortured attitudes, innumerable dark-dyed cigarette stumps, several pocket magazines with bleached wrinkled pages, empty and near-empty medicine bottles and pill vials, rusty hairpins, bobby pins, safety pins, crumpled toothpaste tubes (and a couple for oil paint), a gray toothbrush, a fifty-cent piece and several pennies, the mummy of a mouse, a letter from Picasso, and last of all, from the dark corner behind the bathtub's inside claw, the limp pitiful thing he was seeking.

It was even tinier than he'd thought. He carefully washed the dust and flug off it, but it was clearly dead and its resemblance to Grushenka Stulnikov-Gurevich had become problematical—indeed, Simon decided that someone seeing it now for the first time would think it a freak minnow or monstrous tadpole and nothing more, though mutation or disease had obviously been at work. The illusion of a miniature mermaid still existed in the tapering tail and armlike appendages, but it was faint. He tried to remember what he knew about salamanders—almost nothing, it turned out. He thought of embryos, but his mind veered away from the subject.

He wandered back into the studio carrying the thing in his hand. He climbed the stepladder by the north window and studied the house next door. What windows he could see were dark. He got a very vague impression that the roof had changed. After he had strained his eyes for some time he fancied he could see a faint path of greenish luminescence streaming between the pent-shack and the water-tank, but it was very faint indeed and might only be his vision swimming.

He climbed down the stepladder and stood for a moment weighing the tiny dead thing in his hand. It occurred to him that one of his friends at the university could dig up a zoologist to pass on his find.

But Simon's curiosity was more artistic than scientific. In the end he twisted a bit of cellophane around the thing, placed it on the ledge of his easel and went off to bed ... and to a series of disturbingly erotic dreams.

Next day he got up late and, after breakfasting on black coffee, gloomed around the studio for a while, picking things up and putting them down. He glanced frequently at the stepladder, but resisted the temptation to climb up and have another look next door. Sighing, he thumbtacked a sheet of paper to a drawing board and half-heartedly began blocking in a female figure. It was insipid and lifeless. Stabbing irritably at the heavy curve of the figure's hip, he broke his charcoal. "Damn!" he said, glaring around the room. Abandoning all pretense, he threw the charcoal on the floor and climbed the stepladder. He pressed his nose against the glass.

In daylight, the adjoining roof looked bare and grimy. There was a big transparent pipe running between the water tank and the shack, braced in two places by improvised-looking wooden scaffolding. Listening intently, Simon thought he could hear a motor going in the shack. The water looked sallow green. It reminded Simon of those futuristic algae farms where the stuff is supposed to be pumped through transparent pipes to expose it to sunlight. There seemed to be a transparent top on the water tank too—it was too high for Simon to see, but there was a gleam around the edge. Staring at the pipe again, Simon got the impression there were little things traveling in the water, but he couldn't make them out.

Climbing down in some excitement, Simon got the twist of cellophane from the ledge of the easel and stared at its contents. Wild thoughts were tumbling through his head as he got back up on the stepladder. Sunlight flashed on the greenish water pipe between the tank and the shack, but after the first glance he had no eyes for it. Grushenka Stulnikov-Gurevich had her face tragically pressed to the window of the shack. She was wearing the black dress with high neck and puffed shoulders. At that moment she looked straight at him. She lifted her hands and seemed to speak imploringly. Then she slowly sank from sight as if, it horridly occurred to Simon, into quicksand.

Simon sprang from his chair, heart beating wildly, and ran down the stairs to the street. Two or three passersby paused to study him as he alternately pounded the flaking green door of the Russians' house and leaned on the button. Also watching was the shirt-sleeved driver of a moving van, emblazoned "Stulnikov-Gurevich Enterprises," which almost filled the street in front of the house.

The door opened narrowly. A man with a square black beard frowned out of it. He topped Simon by almost a head.

"Yes?" Ivan the Bomber asked, in a deep, exasperated voice.

"I must see the lady of the house immediately," Simon cried. "Your sister, I believe. She's in danger." He surged forward.

The butt of the Bomber's right palm took him firmly in the chest and he staggered back. The Bomber said coldly, "My sister is—ha!—taking a bath."

Simon cried, "In that case she's drowning!" and surged forward again, but the Bomber's hand stopped him short. "I'll call the police!" Simon shouted, flailing his limbs. The hand at his chest suddenly stopped pushing and began to pull. Gripped by the front of his shirt, Simon felt himself being drawn rapidly inside. "Let go! Help, a kidnapping!" he shouted to the inquisitive faces outside, before the door banged shut.

"No police!" rumbled the Bomber, assisting Simon upstairs.

"Now look here," Simon protested futilely. In the two-story-high living room to his right, the pipes of an organ gleamed golden from the shadows. At the second landing, a disheveled figure met them, glasses twinkling—Vasily the Vodka Breather. He spoke querulously in Russian to Ivan, who replied shortly, then Vasily turned and the three of them crowded up the narrow third flight to the pent-shack. This housed a small noisy machine, perhaps an aerator of some sort, for bubbles were streaming into the transparent pipe where it was connected to the machine; and under the pipe, sitting with an idiot smile on a chair of red plush and gilt, was a pale black-mustached man. An empty clear-glass bottle with a red and gold label lay on the floor at his feet. The opposite side of the room was hidden by a heavy plastic shower curtain. Grushenka Stulnikov-Gurevich was not in view.

Ivan said something explosive, picking up the bottle and staring at it. "Vodka!" he went on. "I have told you not to mix the pipe and the vodka! Now see what you have done!"

"To me it seemed hospitable," said Vasily with an apologetic gesture. "Besides, only one bottle—"

Ducking under the pipe where it crossed the pent-shack, Ivan picked up the pale man and dumped him crosswise in the chair, with his patent-leather shoes sticking up on one side and his plump hands crossed over his chest. "Let him sleep. First we must take down all the apparatus, before the capitalistic police arrive. Now: what to do with this one?" He looked at Simon, and clenched one large and hairy fist.

"Nyet-nyet-nyet," said the Vodka Breather, and went to whisper in Ivan's ear. They both stared at Simon, who felt uncomfortable and began to back toward the door; but Ivan ducked agilely under the pipe and grasped him by the arm, pulling him effortlessly toward the roof exit. "Just come this way if you please, Mr. Gru-ay," said Vasily, hurrying after. As they left the shack, he picked up a kitchen chair.

Crossing the roof, Simon made a sudden effort and wrenched himself free. They caught him again at the edge of the roof, where he had run with nothing clearly in mind, but with his mouth open to yell. Suspended in the grip of the two Russians, with Ivan's meaty palm over his mouth, Simon had a momentary glimpse of the street below. A third bearded figure, Mikhail the Religious, was staring up at them from the sunny sidewalk. The melancholy face, the deep-socketed tormented eyes, and the narrow beard tangled with the dangling crucifix combined to give the effect of a Tolstoy novel's dust-jacket. As they hauled Simon away, he had the impression that a chilly breeze had sprung up and the street had darkened. In his ears was Mikhail's distant, oddly discordant whistling.

Grunting, the two brothers set Simon down on the kitchen chair and slid him across the roof until something hard but resilient touched the top of his head. It was the plastic pipe, through which, peering upward, he could see myriads of tiny polliwog-shapes flitting back and forth.

"Do us a kindness not to make noise," said Ivan, removing his palm. "My brother Vasily will now explain." He went away.

Curiosity as much as shock kept Simon in his chair. Vasily, bobbing his head and smiling, sat down tailor-fashion on the roof in front of him. "First I must tell you, Mr. Gru-ay, that I am specialist in biological sciences. Here you see results of my most successful experiment." He withdrew a round clear-glass bottle from his pocket and unscrewed the top.

"Ah?" said Simon tentatively.

"Indeed yes. In my researches, Mr. Gru-ay, I discovered a chemical which will inhibit growth at any level of embryonic development, producing a viable organism at that point. The basic effect of this chemical is always toward survival at whatever level of development—one cell, a blastula, a worm, a fish, a four-legger. This research, which Lysenko scoffed at when I told him of it, I had no trouble in keeping secret, though at the time I was working as the unhappy collaborator of the godless soviets. But perhaps I am being too technical?"

"Not at all," Simon assured him.

"Good," Vasily said with simple satisfaction and gulped at his bottle. "Meanwhile my brother Mikhail was a religious brother at a monastery near Mount Athos, my Nihilist brother Ivan was in central Europe, while my third brother Lev, who is of commercial talents, had preceded us to the New World, where we always felt it would some day be our destiny to join one another.

"With the aid of brother Ivan, I and my sister Grushenka escaped from Russia. We picked up Mikhail from his monastery and proceeded here, where Lev had become a capitalist business magnate.

"My brothers, Ivan especially, were interested in my research. He had a theory that we could eventually produce hosts of men in this way, whole armies and political parties, all Nihilist and all of them Stulnikov-Gureviches. I assured him that this was impossible, that I could not play Cadmus, for free-swimming forms are one thing, we have the way to feed them in the aqueous medium; but to make fully developed mammals placental nourishment is necessary—that I cannot provide. Yet to please him I begin with (pardon me!) the egg of my sister, that was as good a beginning as any and perhaps it intrigued my vanity. Ivan dreamed his dreams of a Nihilist Stulnikov-Gurevich humanity—it was harmless, as I told myself."

Simon stared at him glassy-eyed. Something rather peculiar was beginning to happen inside his head—about an inch under the point where the cool water-filled plastic pipe pressed down on his scalp. Little ghostly images were darting—delightfully wispy little girl-things, smiling down at him impudently, then flirting away with a quick motion of their mermaid tails.

The sky had been growing steadily darker and now there came the growl of thunder. Against the purple-gray clouds Simon could barely make out the semi-transparent shapes of the polliwogs in the pipe over his head; but the images inside his mind were growing clearer by the minute.

"Ah, we have a storm," Vasily observed as the thunder growled again. "That reminds me of Mikhail, who is much influenced by our Finnish grandmother. He had the belief as a child that he could call up the winds by whistling for them—he even learned special wind musics from her. Later he became a Christian religious—there are great struggles in him. Mikhail objected to my researches when he heard I used the egg of my sister. He said we will produce millions of souls who are not baptized. I asked him how about the water they are in, he replied this is not the same thing, these little swimmers will wriggle in hell eternally. This worried him greatly. We tried to tell him I had not used the egg of my sister, only the egg of a fish.

"But he did not believe this, because my sister changed greatly at the time. She no longer spoke. She put on my mother's bathing costume (we are a family people) and retired to the bathtub all day long. I accepted this—at least in the water she is not violent. Mikhail said, "See, her soul is now split into many unredeemed sub-souls, one each for the little swimmers. There is a sympathy between them—a hypnotic vibration. So long as you keep them near her, in that tank on the roof, this will be. If they were gone from there, far from there, the sub-souls would reunite and Grushenka's soul would be one again." He begged me to stop my research, to dump it in the sea, to scatter it away, but Lev and Ivan demand I keep on. Yet Mikhail warned me that works of evil end in the whirlwind. I am torn and undecided." He gulped at his vodka.

Thunder growled louder. Simon was thinking, dreamily, that if the soul of Grushenka Stulnikov-Gurevich were split into thousands of sub-souls, vibrating hynotically in the nearby water tank, with at least one of them escaping as far as his bathtub, then it was no wonder if Grushenka had a strange attraction for him.

"But that is not yet the worst," Vasily continued. "The hypnotic vibrations of the free-swimming ones in their multitude turn out to have a stimulating effect on any male who is near. Their sub-minds induce dreams of the piquant sort. Lev says that to make money for the work we must sell these dreams to rich men. I protest, but to no avail."

"Lev is maddened for money. Now besides selling the dreams I find he plans to sell the creatures themselves, sell them one by one, but keep enough to sell the dreams too. It is a madness."

The darkness had become that of night. The thunder continued to growl and now it seemed to Simon that it had music in it. Visions swam through his mind to its rhythm—hordes of swimming pygmy souls, of unborn water babies, migrations of miniature mermaids. The pipe hanging between water tank and pent-shack became in his imagination a giant umbilicus or a canal for a monstrous multiple birth. Sitting beneath it, helpless to move, he focused his attention with increasing pleasure on the active, supple, ever more human girl-bodies that swam across his mind. Now more mermaid than tadpole, with bright smiling lips and eyes, long Lorelei-hair trailing behind them, they darted and hovered caressingly. In their wide-cheeked oval faces, he discovered without shock, there was a transcendent resemblance to the features of Grushenka Stulnikov-Gurevich—a younger, milk-skinned maiden of the steppes, with challenging eyes and fingers that brushed against him with delightful shocks....

"So it is for me the great problem," Vasily's distant voice continued. "I see in my work only the pure research, the play of the mind. Lev sees money, Ivan sees dragon teeth—fodder for his political cannon—Mikhail sees unshriven souls, Grushenka sees—who knows?—madness. It is indeed one great problem."

Thunder came again, crashingly this time. The door of the pent-shack opened. Framed in it stood Ivan the Bomber. "Vasily!" he roared. "Do you know what that idiot is doing now?"

As the thunder and his voice trailed off together, Simon became aware at last of the identity of the other sound, which had been growing in volume all the time.

Simultaneously Vasily struggled to his feet.

"The organ!" he cried. "Mikhail is playing the Whirlwind Music! We must stop him!" Pausing only for a last pull at the bottle, he charged into the pent-shack, following Ivan.

Wind was shaking the heavy pipe over Simon's head, tossing him back and forth in the chair. Looking with an effort toward the west, Simon saw the reason: a spinning black pencil of wind that was writing its way toward them in wreckage across the intervening roofs.

The chair fell under him. Stumbling across the roof, he tugged futilely at the door to the pent-shack, then threw himself flat, clawing at the tarpaper.

There was a mounting roar. The top of the water tank went spinning off like a flying saucer. Momentarily, as if it were a giant syringe, the whirlwind dipped into the tank. Simon felt himself sliding across the roof, felt his legs lifting. He fetched up against the roof's low wall and at that moment the wind let go of him and his legs touched tarpaper again.

Gaining his feet numbly, Simon staggered into the leaning pent-shack. The pale man was nowhere to be seen, the plush chair empty. The curtain at the other side of the room had fallen with its rods, revealing a bathtub more antique than Simon's. In the tub, under the window, sat Grushenka. The lightning flares showed her with her chin level with the water, her eyes placidly staring, her mouth opening and closing.

Simon found himself putting his arms around the black-clad figure. With a straining effort he lifted her out of the tub, water sloshing all over his legs, and half carried, half slid with her down the stairs.

He fetched up panting and disheveled at the top landing, his attention riveted by the lightning-illuminated scene in the two-story-high living room below. At the far end of it a dark-robed figure crouched at the console of the mighty organ, like a giant bat at the base of the portico of a black and gold temple. In the center of the room Ivan was in the act of heaving above his head his globular leather case.

Mikhail darted a look over his shoulder and sprang to one side. The projectile crashed against the organ. Mikhail picked himself up, tearing something from his neck. Ivan lunged forward with a roar. Mikhail crashed a fist against his jaw. The Bomber went down and didn't come up. Mikhail unwrapped his crucifix from his fingers and resumed playing.

With a wild cry Simon heaved himself to his feet, stumbled over Grushenka's sodden garments, and pitched headlong down the stairs.

When he came to, the house was empty and the Stulnikov moving van was gone. At the front door he was met by a poker-faced young man who identified himself as a member of the FBI. Simon showed him the globular case Ivan had thrown at the organ. It proved to contain a bowling ball.

The young gentleman listened to his story without changing expression, thanked him warmly, and shooed him out.

The Stulnikov-Gureviches disappeared for good, though not quite without a trace. Simon found this item in the next evening's paper, the first of many he accumulated yearningly in a scrapbook during the following months:

The professor added, "I would like to know where they got them, however. There is clear evidence of mutation, due perhaps to fallout."

Dr. Stulnikov directed his party in a brief but intensive search for overlooked specimens. His charming silent sister, Grushenka Stulnikov, wearing a quaint Latvian swimming costume, explored the shallows of the Delaware.

After collecting as many specimens as possible, the professor and his assistants continued their trip in their unusual camping car. Dr. Stulnikov intends to found a biological research center "in the calm and tolerant atmosphere of the West Coast," he declared.