You browse through the selection and find a costume that you find rather intriguing. It's a set of black leather shorts and a leather vest. You show it to Jack who grins as he sees it. "That's a good one", he says, not going into any details on what that costume might be for. He continues, "You probably should strip completely before turning it on" and shows you the way to the changing booth.
Wondering if Jack has some strange kink or something, you get into the booth. It was a fairly standard booth lit by a light on top with a large mirror and a curtain to offer some privacy. You do as your are told and start to strip. The shorts are about knee long and easily cover your privates, so you should be alright. In no time you are down to your socks. You take another look at the pants. They are mostly black with broad white stripes running down the inner sides. On the outer side there are strange horizontal flaps, almost looking like shark gills. Just above where the knees would be they widen up for a few centimeters with a bell shape. You open their zipper and, without looking you put them on, closing the zipper again. Suddenly you jolt back as you realize that your legs have changed. They are now matte black. Touching them you realize they are now hard, seemingly made from some sort of plastic or ceramic. The remains of your socks hang of them, you really should have gotten them off. Lifting your right foot you realize that they are now tipped with black rubber. Your toes have vanished and what is left looks like stylized boots. Moving them you see that they move along some invisible joints. At the knees, what were the pants turned into a similar kind of material with the wider "bells" mimicking upended boot shafts. Above them the flaps have turned into what looks like vents. The inner white parts are still there, going up to just below your privates. While the pants seem to be made out a similar material than your legs, there still is a zipper on them. Opening it reveals what your privates have become, a red silicone rubber rod with a sculpted ball sac made from seemingly the same material. Trying to push down your pants reveals that somehow they seem to be stuck. In panic you close them again only to realize what had happened on your back. A huge fluffy tail has grown there, stretching from the extension of your spinal cord. The fluff is almost as wide as yourself and suddenly you realize that you can move it.
"Are you alright in there", Jack asks. "I... I guess so", you answer a bit hesitantly. Jack replies, "Be sure to put on the whole costume".
You think to yourself, this must be some sort of trick. There's still the vest left and you decide to watch it more closely. You pick it up and put your left arm through its sleeve. It seems to go in just fine, but what comes out of it has black fur all over it, longer on the arms, and much shorter on the hands. You pull back your arm and it comes back human again. You decide to put your left arm though it completely. Predictably it is now covered in black fur. Looking at your fingers and palms you realize that they have black skin pads, allowing for fine grips, just like with normal hands. You decide to try the other arm, too and slip on the vest. Your right arm however looks a lot different now. It seems to be mechanical, just like your legs, consisting of the same matte black material. Your hands also have rubber pads, but the palm is white, just like area at your legs. Before you have a chance to examine it further, you are interrupted by a wave of changes going down your chest. Fur quickly grows, black on your sides, with white fur on your belly and down a stripe on your back below the vest.
Then another wave, your head starts to contour as it gets squished and reformed. Your nose and mouth push forwards forming a muzzle as your ears grow becoming a bit more pointy. Your hair also grows at lot, particularly in the mid section making it look like a white mohawk extending the white stripe on your back to your hair. Looking at yourself in the mirror you see that your head is the one of an anthropomorphic skunk.
Then suddenly another wave of changes hits you. This time it opens up your mind. You realize what those mechanical limbs are. You gain control over the computers that control them. You open up the curtain and reveal yourself to Jack.