Rifling through the t-shirts you laid out, you notice one which seems longer than most of the others, and seems cut almost like a tunic at the bottom. It has two colors, the top of the t-shirt nearly matching your skin color exactly, while there is a rather wide stripe around the bottom in a rich dark brown color. Even if this t-shirt causes some change like the blue t-shirt, you have no clue from the color or the pattern what that change could be. You hold it up in front of you, and notice that the top of the dark brown stripe hits you just above your hips. While changing into a man earlier was a shock, it doesn't seem to have harmed you any, and there is no guarantee this t-shirt would do anything. It might just be the blue t-shirt alone which has odd powers. You debate removing your pants and underwear before putting on the shirt, but your last change didn't harm them either, so you don't see a point. Pulling off your old top and tossing it on the bed, you pull the long t-shirt over your head.
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The first thing you notice is that your perspective seems to have shifted. Your line of sight is nearly even with the top of the door frame. Perhaps the t-shirt makes the wearer taller. Did it stretch you out? Maybe that is why your spine feels a bit odd. However, your analysis is interrupted by a strange chill. You look down to find that your torso is completely nude. Not only is the t-shirt missing, but your bra has disappeared as well. Although you seem more toned and muscular, you do not have time to appreciate this fact, since as you look down, you notice that while the t-shirt is gone, the brown stripe seems to have remained. In fact, it seems to have made your hips wider, and larger, and...hairy? You lean forward a bit and reach down to touch your hips, which is when you catch sight of....
...two hooves. Below what was once your hips are now two long, slender but muscular legs leading down to shiny black hooves. Incredulous, you try to lift one, but even though you feel your mass shift, neither of the legs you are looking at move. You are confused for a moment, since you have the feeling that you lifted a leg, so you stop to think, which results in you lowering the leg you thought you lifted. From a few feet behind you you hear a soft thump, and have the sensation of mass shifting again. Although you are almost afraid to do so, you have to confirm the suspicion which has suddenly engulfed your brain.
You look back over your shoulder, and cannot help but stare in utter disbelief. Stretching out behind you is the body of a dark chocolate-brown, muscled, magnificent...horse. As if to punctuate the point, the tail at the end of the horse body swishes back and forth, and somehow you not only see it but feel it. Now you know why you are so tall. Your nude torso is now seamlessly connected to the body of a horse; the t-shirt has changed you into a centauress. You reach back with you hand and run it gingerly over the horse body, shivering not only at the feel of the horsehair against your hand, but at the feel of your hand through the horse body. You want to get a clearer look at what happened, so you try to move towards the bathroom, thankful that you are on the ground floor. You can only imagine what the weight might have done to the apartment were you on a higher level.
As you attempt to walk, you realize that having six limbs, four of them legs, is not very easy to coordinate. You cannot seem to focus on your arms and your legs at the same time, so you purposefully let your hands hang while you concentrate purely on the four legs. You cannot quite remember how horses walk, but your mass seems to dicate that you not shift your weight too much. Moving one leg at a time, in stops and starts, you finally make it to the bathroom door. Although it is narrower than the other doorways in your apartment, you manage to squeeze yourself through, having to duck as well in order to not bang your head on the doorframe. Although startled by the "clip-clop" of the hooves on your bathroom tile, you continue in. Grateful that your bathroom is fairly large, you get your first look at your body in the mirror.
Although you cannot see your lower legs and hooves in the mirror, you can see them well enough directly, so instead you focus on the point where your body melts into that of a horse. The transition seems smooth and natural, waves of horsehair curving over your former hips, which are now the broad shoulders of the horse body. You run your hands over the area and find no indication that the horse's body is in any way not your own. Your wonder and reverie are broken by the sound of a loud knock on your apartment door.
"Maintenance," you hear a voice say, and for an instant, you nearly panic. You cannot be seen like this! While you almost hope the person will leave, the knock comes again, more insistent and louder. "Just a minute," you shout back, hoping that it is true. You hands scramble around your body, searching for a t-shirt that is no longer there. Shaking your head, you remember that bottom of the t-shirt fell slightly below your hips. You reach down worriedly and search with your fingers across the horse's shoulders, growing desperate.
As if in response, your fingers slide under a lip of fabric which definitely was not there a second ago. Not bothering to wonder why, you yank the shirt over your head, and find yourself a normal human girl once again, standing in her bra and trousers in her bathroom. Running out, you toss the t-shirt on the bed and grab the one you were wearing earlier, pulling it on. You run to the door and open it, finding a man in a workman's uniform standing there, a toolbag in his hand. "Gotta check the pipes," he says nonchalantly.
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As the maintenance man enters the bathroom to set down his tools, you begin gathering up the t-shirts on the bed, not sure you want them out while someone else is around. "Guess you live here alone, huh?" you hear a voice say behind you. You turn rather quickly, a bit startled, to see the maintenance man standing there, grinning. You are not sure why, but you feel uncomfortable about his question. "My boyfriend is coming by in a bit," you say, hoping your lie sounds convincing. "Oh really," he says, still grinning, as you involuntarily take a step back, wanting to put anything, even the bed, between the two of you, since you have nothing nearby with which to defend yourself. You feel your panic rising as he takes a step towards you, but you don't want to let him know. "Can you finish up kind of quick? I have to meet friends soon," you bluff. "Quick, huh?" he says, with a disconcerting smirk. As he steps toward you again, you begin to move back, and as you come around the other corner of the bed, out of the corner of your eye you spot the t-shirt with the dark brown stripe hanging over that side of the bed where you tossed it. You grab for it just as he grabs for you. Before he can pin your arms, you yank the shirt over your head.
The maintenance man blinks in disbelief for a second as, instead of pinning a girl to the carpet, he is now hanging off the nude body of a half-human, half-horse. As fear now invades his eyes, he lets go of you and takes a few steps back. You, however, have lost your fear now that you are the bigger individual, and in its place grows fury. Not bothering to think about how to move your horse body, you whirl yourself around the bed, and aiming over your shoulder, lift your hind legs off the ground to kick the maintenance man squarely in the chest. He is thrown back against the wall by the force and hits his head, rendering him unconscious. You walk over, still a bit unsteady, and tower over him. For what he tried to do to you, you are sorely tempted to trample him to death. However, this desire is tempered by the fact that you will have to explain what happened somehow. Claiming a man was run over by horses in a suburban apartment would not be very convincing. Reaching down, this time you find the edge of the t-shirt relatively easily, and pull it over your head.
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"We've been trying to get this guy for a while," the police officer says to you. "That's his M.O., entering apartments posing as a maintenance man. You were lucky you managed to get your hand on that piece of bed frame. If you hadn't hit him...well, you probably have some idea what he would have done to you. Are you sure you'll be okay on your own? Do you want us to call anyone?"
You nod to show you are okay, and shake your head in response to the offer to contact someone. You are still in a bit of shock from everything that happened, but glad that you had the presence of mind to take the extra metal pieces used to expand your bed frame out of your closet and place them by the wall of your bedroom. You told the police that you had left them there from when your bed was delivered a few days ago, and when attacked, you reached for them and landed a few good blows on the man, knocking him out. You hope that the man remembers nothing of what really happened, and considering the concussion you gave him, that is a pretty good bet. At any rate, who would believe a girl changed into a centauress and kicked him? You are fairly certain your secret is safe.
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After the police leave, you collapse on your bed, ignoring the pile of t-shirts nearby where you dropped them. The only one left on the bed is the one with the dark brown stripe. You turn on your side, contemplating the t-shirt. What had seemed like merely a unique article had turned into a life-saver. You sit up and lay the shirt across your lap, then look over at the pile of t-shirts on the floor. Considering the possibilities, you decide to...