"Tonight it's time for a special experiment," said Doc patting me on my head.
"Are you sure you can assist me on that matter, Nancy?"
I tried to nod my head, though my current posture didn't allow much movement. I was standing on my knees on a metal lab table, my neck, wrists and ankles were locked wide apart in thick black plastic stocks fixed to the opposite sides of the table top. I was bent over the padded metal frame running across the table, my head was fixed on a level with my feet. My bottom was protruding back and up and my breasts were dangling below, nipples touching the cold metal surface. My white lab coat laid folded properly on a couch beside the table as well as blouse, skirt and undies. Shoes went under the couch. I was totally naked, for the sake of purity of the experiment.
" Good. Finally the seeds have arrived, and some of them are in pretty good condition. The flow of the experiment itself is quite simple... I'd better tell you all from the beginning, so you can fill the laboratory log later. I hate the paperwork, you know..."
"Well," said Doc unpacking the large wooden crate delivered today. I tried to turn my head slightly to see what's inside but failed. The only sound I heard was shuffle of some kind of wooden shavings.
"In distant land of Zeronia there is some peculiar weed. Local peasants call it Jabuca "Sand eater" and fight it as they can. You see, Jabuca's life cycle interferes with Zeronian agriculture. Its seed has quite a hard shell and it can lay in dry soil for years waiting for the rainfall. When it gets enough water it starts to grow rapidly, consuming a lot of liquid and nutritions from surrounding soil. In one night it can grow a thick trunk about two feet high and quite extensive root system. When the rain stops the weed withers quickly. Jabuca is endemical to Zeronian climate and soil, it can't grow anywhere else. I studied the Zeronian ecosystem and got some ideas about introducing Jabuca to our native environment."
"But how it concerns our field of study?" I asked. My voice was somewhat coarse from stocks pressure.
" Why, researching the possibilities of using Jabuca seed surely adds a lot to my new university course: "Exotic torture devices and their application to modern women". It can attract new sponsors to my research projects. We can sell the seeds to adult stores. And finally, we both like the process."
" Yes, sure. Well, what's about introduction of Jabuca?"
" You see, I found out that humidity, temperature and chemical conditions of Zeronian fields in rain season are very similar to those in human rectum. Particulary a woman's rectum. Oh, I can see from your eyes, you've got the point. This is where you're going to help me. These stocks and frame fix you in proper position to insert seed and observe its growth. It isn't so uncomfortable, is it?"
" Not at all."
" Good. I also installed a camera pointing at your anal opening. It will film the process making a shot per minute. I think it will take no more than six hours. Well, are you ready, Nancy?"
" Yes, I think..."
With a loud clap Doc put on medical latex gloves. "I'm sorry, I can't use a lubricant. The seed may not sprout in wrong chemical conditions. Well, relax your sphincter, Nancy. Here it goes..."
Doc parted my ass cheeks with one hand and pressed some hard object against my tight rear hole. I tried to relax as the pressure raised but it still hurt more than I expected. I squirmed.
" Doc, I thought it was a little seed!"
" Actually, it looks more like a nut. No more than inch in diameter."
" Sure, it has to be quite massive to live over drought."
" Calm down, Nancy, it's almost over."
I thought I heard a pop when the nut came through my sphincter muscles.
" It's in. Here, I make sure it's deep enough. It's pity, I'm not a piano player, my fingers are too short... Well, I think it's ok. Now we have to water it properly..."
After a hard wooden... ball, I assume... the cool smooth rubber nuzzle of an enema bag felt really pleasant. Doc squeezed about a glass of water into me, I guess.
" You have to hold water in for a while. It won't take long. So, it seems all is set. Now I turn the camera on... Well, Nancy, have fun. I have busy day ahead, three lectures... Those freshmen..."
" You're filming me, so..."
" Yes, I'll watch the show later. Be a good girl. I'll come back in a few hours."
Doc took off the lab coat, hung it beside the door and left. The key in the lockhole clicked and so clicked the camera for the first time.
* * *
"Doc! It's good you're back at last! Take it out of me, please!"
" Shoo, Nancy, what's the matter?"
" Can't you see? Am I alright?"
" Well, let's see... It's amazing! Honestly, I expected it to grow more intensively inside the human body, but it's..."
" Please, Doc, hurry, take it out! I can't bear it!"
" Calm down, it's ok. I have to measure it first, at least outside part, and make some marks... Is the camera working? Yes, it is... Where is my ruler I'd like to know..."
Doc walked around me muttering to himself. I've known him for quite a long time, it's almost impossible to wake him up from his scientific delirium. I tugged sharply at stocks trying to break free. I whimpered as heavy trunk protruding from my ass rocked back and forth. Hopeless. I tried it before, multiple times. Desperate, I hit the table with my knees and ankles trying to get Doc's attention. After a few tries I succeded.
" Nancy, tell me, how do you feel?"
" How do I feel? Like my ass is being raped with a 3 inch thick tree trunk!"
" Well, that was a near miss. According to my measurements, it's 3.38 inches."
" My God, Doc, please, take it out! It's tearing me apart!"
" The things aren't so bad, Nancy. I don't see any blood yet. It wasn't a sudden intrusion. It grows rather slowly, pushing your rectum tissues wider and wider. You probably even didn't realize it until it was too wide."
" Yes, it was even enjoyable at first. I felt the nut break and soft sprout started to find its way out of me. I think some roots crept down my bowels but I'm not sure. The sprout popped out of my anus, I felt slight pulsation in its still soft trunk. Then it started to grow branches, they hung down my thighs, tickled my skin in tender laces."
" Probably it started to seek more water, as one of its branches went down your vagina."
" I know, Doc! I liked it at first, but it's too much! It grows through me, reaching the most private places! And the main trunk just too thick and gnarly!"
" Well, at least you don't have to worry about your diet for the next couple of weeks. The plant has taken quite a lot of nutritions from your body. Speaking of nutritions, I can't take it out of you in its present state. It's too thick and deep rooted."
" Doc! Do something!"
" That's what I'm going to do. We have to kill the plant. It will dry out and shrink, and I will be able to pluck it out of your anus. Just where did I put that can?.."
" Yes, a herbicide. You have to swallow it. It will take quite a lot of liquid to finish off the Jabuca."
Doc approached carrying one gallon plastic can...