The crawling sensation rapidly spreads all over your body, with the ripples under your skin becoming more pronounced with each passing second, and it only gets worse from there. Your arms and legs begin to move against your will, only a little bit at first, then with increasing violence until, unable to maintain your balance, you are sent tumbling to the floor. You barely notice as your head strikes the concrete, because you are too focused on the fact that whatever is happening inside of you is accompanied by a growing pressure in your chest, as if you were being squeezed inside of a giant vice, leaving you unable to breathe in more than a tiny gasp of air at a time.
There is nothing you can do but lay there and try to maintain your tenuous grasp on consciousness as your limbs continue to flail around more and more wildly, completely out of your control. You ache right down to the bone as you are stretched and pulled around in ways that nature never intended you to be. Suddenly, there is a long, horrifying series of wet popping and cracking sounds, like breaking wet twigs or celery, and even in your current state you know that it can only be the sound of your skeleton coming apart. It seems to go on forever, but strangely it brings with it a reduction of pain rather than an increase. Less fortunately though, the motions of your body becomes more inhuman as with each new snapping sound your extremities begin bending in another new place.
Then, everything stops. One moment you're flailing around uncontrollably and the next you're lying spread-eagled on the floor, perfectly still. It's so sudden that it is almost as if somebody flipped a switch from "on" to "off." At first, you are afraid to believe that it's over, but as the minutes go by and your limbs offer no more involuntary movements, you begin to relax. Your skin doesn't feel like it's crawling anymore, and the dizziness is gone. Nothing hurts, not even where you hit your head on the floor. In fact, aside from being tired and thirsty, you actually feel pretty good.
Maybe you imagined it all, you think to yourself as sit up and begin dusting the dirt and cobwebs off of your clothes. Maybe the seed you swallowed had some sort of fast-acting psychotropic chemical in it and the last however many minutes were just a bad trip. Yeah, it must have been. It couldn't have been real, because if you had really just been thrashing around until you broke every bone in your body, then you wouldn't be able to sit here and calmly pick old dead bugs off your shirt like you are right now. Right?
You look down at your hands to reassure yourself that your bizarre experience really had been all in your mind. They're a bit on the filthy side, but they are the right shape and size and have the right number of fingers. Nothing about them seems to be out of the ordinary. Then you ball them into fists, and just like that the illusion is shattered, because your hands only look normal as long as you hold them spread out flat. As soon as you move them, you can see that they don't bend at the joints the way that they did less than half an hour ago. As far as you can tell there aren't any joints there to bend. Instead, your fingers curve smoothly along their entire length, each one wrapping itself into a tight spiral. As soon as you stop consciously trying to make a fist, your fingers spring back straight again, like pulling back a tree branch and then letting it go. Experimentation reveals that the bend backwards just as easily as forwards. Each of your arms is the same way, normal looking as long as you kept them straight but actually a single flexible unit all the way to your shoulder, bending and curling in any direction that you think of and then springing back as soon as you relax.
The enormity of your situation finally sinks in and you stagger to your feet in a panic, discovering along the way that your feet are in exactly the same condition that your arms are. Your legs are fortunately stiff enough to keep you from immediately falling on your face, there's a bit of a learning curve before you can achieve locomotion. You had never appreciated how elegantly simple human leg bones and knees were until now, when you had to figure out how to walk without them. However, fear is a good motivator, and in practically no time at all you have coordinated yourself well enough to stumble up the stairs and out of the basement.