Deep in the Brazilian jungle, camouflaged to appear harmless, sits the laboratory of Dr. Heinz Ormschmidt, noted German microbiologist. The Nazi regime has transplanted Herr Doktor and his lab here to avoid the Allied air raids while he, along with his assistant, the beautiful, voluptuous and totally lesbian Heidi Von Furpuss work on an experiment vital to the Nazi war effort. By combining genetics, cloning, and mind control, the Nazis hope to develop an undetectable means of destroying allied shipping. The lab contains one large tank of about 10 meters by 20 meters by 2 meters filled with a water solution along with several smaller tanks built into the walls of the facility. Many tables containing bottles, test tubes, and other scientific equipment furnish the room along with shelves containing hundreds of small bottles that contain genetic material, eggs and sperm of various fish and animal life including human. Meanwhile, the Allied intelligence departments have received information about strange happening in the jungle and, fearing it may be linked to A-bomb experiments, are preparing an assault force to investigate and destroy any Nazi facilities they find.

After laboring for months, the doktor can see solid results. Hundreds of combinations tried and failed, now success as the genetically engineered creature in the large tank was living under it's own power. His growth drug had accelerated a normal growth rate from years to a matter of weeks. A fully developed creature, prototype of a new species, could now be trained for the top secret mission. Hitler's plan was one huge step closer to reality. Der Fuhrer wanted a creature strong enough to carry a 100 lb magnetic limpet mine while fast enough to catch merchant shipping attach the mine and escape before detonation blows the bottom out of the ship, and trainable to work for the Nazis. Now the doktor thought he had achieved all the goals. The creature in the tank could easily carry a mine or two on it's back and was faster in the water than any merchant vessel and it had a mind that could be molded to the Nazi will. An army of these creatures could bring England to her knees where the U-boats could not because the Allies could not conceive of their existence and if they had known, there still was no way to detect the silent assassins. During the last two weeks the doktor and Heidi had been training their creation and the creature proved very intelligent, far more than the dolphins that had been tried and rejected. What the doktor hadn't planned on was the primal urgings of the genetic donors emerging in his creature. It was a dangerous combination he had come up with, by combining genetic material from shark, barracuda and homosapiens the creature swimming in the tank had been manufactured, as it will, to his specifications. From head to tail it was just over six feet in length and weighed about 140 lbs. He had created a living version of the mythical mermaid. The female creature had the upper torso of a woman blending to a lower body resembling a large fish. The Germanic genes had produced a strikingly beautiful blue eyed head covered in cascades of wet blond hair. The nose was small and membranes cover the nostrils when in water. Her mouth was larger than normal though not unattractive with large blood red lips that covered her sharp teeth, a result of her barracuda genes. Her neck was long and thicker than a human neck with rows of gill flaps down each side. Her chest was all human with the exception of the gauzie fin that rose from her backbone from just below the neck to where her not quite human ass crack began. A pair of firm pink 40 inch breasts topped with big brown nipples graced the front of her chest and her waist necked down to 26 inches before flaring out to modified hips. At this point the transformation was most evident. Her coloring changed to silver bluegreen and the soft skin began to change to small scales. Except for the scales and the fact that she had no crotch her ass appeared human and in between the bumps of her ass checks was an orifice covered by twin membranes. This was the creatures vagina and her shit hole was down near her tailfin.

Thinking his creature perfect for the task, the doktor had taken blood samples from her and now had thousands of clones in his incubation tanks. After the tests were complete on his prototype subject, a few hundred would be force grown and trained. The rest would be released to the sea to fend for themselves.

He found out just how short sighted he had been one day while training his new pet. Unfortunately for him, it was a lethal mistake. It had been late and the exhausted Heidi had gone to retire. After stripping naked she sat on the toilet while her warm yellow piss sprinkled out over her pussy lips. She struck such a stunning picture that many men would have swum through a mile of that golden liquid just to see where it came from. It would have been a wasted effort, Heidi preferred her own gender when it came to sex. She stood her five foot eight inch, 140 lb body under the cool shower washing away the days dirt from her firm tanned 38 inch tits. Lathering up, she massaged the firm swell of her flat belly, down her long legs and back up her thighs, cleaning her clit and asshole. The shower complete, she dried off, giving her breasts and pussy extra attention with the soft towel before climbing into bed, sleeping nude, as was her habit in the hot climate. She had teased the doctor many times to a fever pitch only to turn him away when he wanted release from his sexual tension. She knew that he spied on her when she slept naked and jerked off dreaming of plunging between her satin thighs. the cum stains outside her bedchamber were proof enough that she was driving him wild with lust. He considered raping the teasing tramp but she was never out of arms reach of her trusty 9mm Luger pistol.

The doktor had been working on motor skills with the mermaid and was in the tank with her in swim shorts when she began to swim around his legs, pressing her breasts against him. The surprised man, although sixty, was still male and his cock began to grow. Sensing his arousal the mermaid backed her fish cunt up to his cock and swayed side to side then turned and pulled down his shorts with her long webbed fingers. Her cavernous mouth opened and took in all of his German sausage. With her hands pinning his ass forward he let himself be sucked off by the she creature but before he could cum she flipped her self around, bent her body at a sharp angle and drove her fish cunt on the hard shlong. The scales scratched his crotch but the rutting man didn't care. He had been without a woman for months; the sexy Heidi drove him crazy with lust but would have none of his advances. The mermaid may not have been as beautiful as Heidi but her cunt was hot, wet and willing. The hybrid beauty gave out a little yelp as her hymen met and was ruptured by the hard male probe then she settled into a rhythmic pumping of her muscled ass on the doktor's penis. It was kinky sex, he thought but it sure beat the hell out of using the palm of his hand. He pumped the fish woman for all he was worth and let fly a load of hot sticky cum up her virgin qwim. The mermaid writhed in the water as she felt the mating goo squirt into her womb. It was over to soon and she was far from satisfied. Slipping off the shrinking shlong she turned and tried to orally revive his tool, she licked his cock clean and fondled his balls but the guy was old and out of shape, he could not respond; then her instincts told her what to do next.

Heidi was laying on her bunk tweaking her turgid nipples with one hand and using a test tube as a dildo between her soft flaring thighs and dreaming of nights back in Germany when she and some of her girlfriends would go to bars and tease the men there till not a flaccid cock remained, then the teasing tramps would leave the men high and dry and spend the evening in their apartment laughing about their cruelty as they tongue and finger fucked each other. Now alone, she had to make do with lab equipment and her imagination. At times she wished the doktor had ordered bigger test tubes. She sorely missed the company of another woman to share her bed. In the months she had been stuck in this God forsaken jungle only one opportunity for sexual release had presented itself. A young native girl made the mistake of wandering too close to the lab when Heidi was outside sunning her lush nude body under the noon skys. The olive skinned teenage girl had never seen a blond woman in her life so she stopped to stare, concealed by some bushes. Heidi lay on her back with her feet to the girl. The Nazi's long legs were slightly spread and the native could just make out the sweet pink pussy between the well muscled thighs.

A rustling in the bushes alerted Heidi and she opened her eyes, making out a shape trying to hide. Reaching for her ever present Luger, Heidi sprang to her feet and commanded the intruder to show it's self. The frightened girl slowly stepped out from her hiding spot with arms raised. Heidi quickly appraised the spy and saw she was not an immediate threat. The girl was too young and clearly had no weapons. She was fourteen at most, slim and lithe. She wore a short, wrap around, skirt like garment and nothing else. Her bare chest sprouted a pair of just developing tits, small and rock hard. Long straight black hair hung nearly to her waist. In three or four years she would develop into a sultry native beauty but Heidi didn't have time to wait. The Nazi slut motioned with her pistol for the girl to approach. When the girl was within arms reach, Heidi put down her gun and grabbed the girl by the hair. She forced the girl to her knees and shoved her face into Heidi's waiting blond muff. Heidi used her grip on the native's head to grind the girl's mouth into her hot pussy. At first the young native girl fought back but soon her struggles were replaced with willing participation. The girl used her free hands to drop her skirt then she clasped Heidi's firm ass and spread her cheeks. Soon two slim fingers were pushing into the Nazi's tight asshole. Heidi squealed in pleasure and released her bladder. The hot piss cascaded over the native's face and she tried to swallow all she could. By now, Heidi's legs were quivering and she had to lay back. The young girl followed her down and sat on the Nazi's face. Heidi grabbed her olive thighs and drilled a virgin pussy with a well trained Aryan tongue. She worked the girl's cunt for a few minutes then had the native get on hands and knees. Heidi mounted the girl like a dog in heat, slamming her cunt against the native's small ass. The girl turned over and Heidi dropped down on her. The big German tits dwarfed the girl's small breasts and Heidi's full lips covered the small girls mouth. The middle digit of Heidi's left hand probed a tight cunt and was stopped by her hymen. The young girl didn't realize she was near an orgasm and it struck the moment Heidi rammed through her virgin shield. The girl had three finger of her hand in Heidi's twat when the orgasm overwhelmed her and she clasped her hands into fists. The vise clamp on her cunt triggered Heidi's climax and the two interlocked females rolled about in the grass, writhing in lust.

As the lust subsided, Heidi began to think a little more clearly. While the girl was not a threat, she could tell others and compromise the mission. If that happened, Heidi would face the wrath on the German High Command and she had no wish to surrender her tender body to the torments of the Gestapo. So, after the two rutting females finished their fuckfest and the girl walked back toward the jungle, Heidi raised her pistol and fired. The bullet hit the native in the lower back and spun her half around. Down on one knee, she grimaced in pain and looked at Heidi in confusion. The remorseless Nazi bitch, knowing it was her or the native, took careful aim and fired again, striking the girl between her boobs. The native flipped backward, arched her back once and sprawled out dead. Heidi dumped the body in the woods and told the doktor she had shot at an animal to scare it away from her.

When the scream tore through the lab it startled her back to the present. Pulling the glass cock from her golden haired snatch, she ran naked back to the lab with her long blond hair streaming down to her full hips, and large firm tits jiggling with her cadence. Bursting into the room with her Luger in hand she was horrified to see the bloody body of the doktor, dead from blood loss and heart failure, floating in the pool with his genitals gone. One look at the bloody mouth of the mermaid now backed into the far corner of the tank and she knew what had happened, the barracuda gene had emerged. The mermaid looked almost as startled at the events as Heidi. She was holding her head and sobbing while viewing her dead creator. Heidi pointed her Luger at the long hard nipple of the mermaid's blood stained left tit while she tried to make sense of what had happened and what to do next. One thing was certain, if the fishwoman so much as moved, she would end the experiment permanently. Before the trigger could be pulled and a 9mm slug rip through the genetically engineered creature's firm flesh and ruin years of work, Heidi got another shock as the mermaid spoke. "Please no" implored the targeted killer, her hands outstretched. The stunned Heidi lowered the weapon, she knew their creature was intelligent but never dreamed it was capable of learning a spoken language it such a short time. "I don't know what made me do it, something told me to mate and kill, I couldn't help myself, please don't hurt me" continued the fishwoman.

It was starting to make some sense, the mermaid in the tank had the body and urges of an adult but her mind hadn't yet caught up, thus the revulsion of what she had just done. Soon however, she would mate, kill, and devour without a pang of remorse. "Very well, I won't shoot but we must discover why this happened" Heidi thought something like this might happen because of the reproductive urges of the host genes used but the departed doktor had dismissed her views and reminded her she was just an assistant. If her thesis was true she need not fear the mermaid as only males would arouse the killing instinct. The next morning she would test her theory but first she had to get rid off the doktors body. With the mermaid's help the body was pushed out of the tank and Heidi dragged it to the acid pit used to dispose of failed experiments.

By the next morning the tanks filters had cleaned out any blood and the water was again clean, blue and warm. The lithe mermaid was lazily swimming about as Heidi approached and appraised the naked creature that fate had made her's. Staring at the supple form in the tank, Heidi began to get a burning urge deep between her legs for she also had been without real sex for a long time, and even though she had many lesbian lovers, she hesitated remembering the doktor fate. The mermaid seemed to read her mind as she held out her arms and said "You have nothing to fear from me, you spared my life and we shall be friends and lovers". "I believe you", responded Heidi "and I will call you Giesle after my old lover in Germany". "Let's really get to know each other Ok". The mermaid nodded "Giesle"," I like my new name, please, Heidi come in and join me". Heidi removed her lab jacket and white shorts to reveal her perfect body and climbed the ladder to the tank. As she threw her long leg over the tank top the admiring mermaid had a closeup view of her pink lipped pussy. Then as the long legs of Heidi lowered into the water, the head of Giesle came up between them and sought out the soft twat with her long tongue. Heidi moaned her pleasure as the tongue explored the sweet recesses of her hot box. "Oh yes", she thought, "This is much better than a piece of glass". The two females spent most of the morning exploring each others bodies with Giesle laying belly down on a edge of the tank so Heidi could tongue fuck the mermaids clit without drowning. They rolled about in the warm water with their breasts pressed together and their hands groping the hidden recesses of their genitals. Both bitches were quivering near extasy as their tongues explored the depths of their mouths and the big mermaid exploded in orgasm as Heidi switched her tongue to flicking the neck gills of her new lover. Heidi's first orgasm came when Giesle swam through her spread legs and tickled her pussy lips with her dorsal fin. With long webbed fingers up her clit and ass she came a second time. The big mermaid tits squired milk down Heidi's throat as she suckled Giesle while dildoing her to another orgasm. The time was getting late and after multiple orgasms both females needed rest as Heidi climbed from the pool, her long hair and pussy both dripping water on the floor. Neither bitch knew they would never have the chance to discover the reason for the attack on the doktor or find the sweet bliss of interspecies love again as fate was about to have the dice come up snake eyes.