Everybody stared at the two gorgeous blonde women strolling casually along the beach. Not because they were holding hands. It's not that unusual for women to hold hands when they're walking together, especially when they're friends, or -- like these two -- sisters. Not because they were beautiful. Though they were beautiful -- both in their early twenties, skin so tight and smooth, taught bellies, breasts high and firm, with just a hint of a jiggle as they walked. Not even because they were rich and famous. Though they were rich -- and, therefore, at least just a little bit famous.

No, it was because they were twins. Identical, in every feature. Their hair, their eyes, the shapes of their bodies. They even walked in unison -- left foot, a bit of a pause, right foot, a tilt of the hips. Dressed in identical thongs -- bottoms only, as this was a tops-optional beach on the Mediterranean -- just little wisps of shimmering, sky blue cloth. They presented such a perfect double image that some people who wore glasses, took them off and checked, to make sure nothing was out of alignment.

Yet there was something... Was the one twin's thong just a little bit tighter? Outlining the lips of her barely-hidden pussy just a little more than her sister's? Her gaze, a little more straight-ahead and unfocused? -- while her sister's attention wandered from the warm ocean, to the sand, to the people ahead, to the children playing, to her twin's face, then out to the horizon.

With twins, they say, there is always a dominant one -- the leader, that the other twin goes along with, agrees to, matches. Often, it's the firstborn of the two -- but not always. With Cindy and Linda, this was true -- but not for the usual reasons.

They continued their walk, at a leisurely pace, the late afternoon sun at their backs. With every step, Cindy's tight thong tugged on the hidden circlet that ringed her clitoris. Left foot, a bit of a pause, right foot, a tilt of the hips. Tug... pause... tug... a rub against the cloth of her thong. So gentle. So impossible to ignore. The little marble sewn into the inside of the back of her thong pressed against her anus, teasing with every step. Tap, a bit of a pause, tap, glide. So impossible to think. Just follow her sister Linda's steps, let her hand gently guide their direction. The shimmering blue cloth disguised the spot of wetness continually dribbling from her pussy. Her nipples were taut, jutting out, continually aching. So were Linda's nipples -- but the cause was different.

Linda guided her twin as they walked along the edge of the water, listening to the barely-suppressed panting that was Cindy's breathing. She knew that with every step, every shift of position, Cindy was being stimulated repeatedly, relentlessly. Linda looked around, enjoying the delightful view of the sky, the ocean, the nearly-naked bodies -- many beautiful, many not so beautiful. She knew people stared at them. It excited her. Even more exciting that they had no idea of the power she held over Cindy. The power they agreed would last a year. And that year was coming to an end.

They reached the gate to the private stairway, leading up to their beach house. Linda let go of Cindy's hand, and unhooked the tiny key ring attached to the right strap of her own thong. She opened the gate, led the panting Cindy through, then closed and locked the gate. Step by gentle step, they ascended the long stairway, all of wood painted a light blue, but weathered by years in the sun and wind. At the top, Linda unlocked the door, again led Cindy through, closed and locked the door.

Once inside, Cindy immediately dropped to the floor on her hands and knees, and crawled alongside her sister. Her eyes were still unfocused, her mind barely aware of where she was -- only that she was next to her sister. Her mistress. Her owner.

Poor little rich girls, Cindy and Linda. Daddy passed away when they were only two, not even a memory in their heads, known only by his appearance in the family photos, and the big portrait hanging over the fireplace mantle back home, in the family mansion. Mama had no time for them, being always away on some trip, whether for one of her many charitable causes or just on a vacation. Taking babies along would have been inconvenient. And by the time the girls were older, Mama had not acquired the habit of thinking about them as traveling companions. Raised by nannies, educated at boarding schools, as the girls entered adulthood they were entirely independent of all family ties. Except, of course, money. Something they never had to worry about.

Finding something interesting to do -- that was another matter.

They had played little "follow the leader" games all their lives. Somewhere along the line, as emerging grown-ups, the games became subtly more and more sexual. Going out with boys -- or girls -- and switching dates. Daring each other to push the envelope just a little bit farther, try more outlandish things. Each watching the other having sex, in a hotel or car. Exchanging partners. Playing with each other, while their dates watched, or screwed them from behind. Some experiments with bondage and discipline. With hypnosis, mind control. They both decided they liked that -- a lot. They played little dominance games with each other more and more. Sometimes Cindy was the mistress, sometimes Linda.

Then they hit on the idea of "the agreement."

For one year, one of them would be the dominant partner, the other the submissive. For a full twelve months, one of them would be mistress, the other slave. At the end of the year, they would switch. A game of "spin the dildo" decided that they would start out with Cindy as the slave, Linda as the mistress.

Today was the anniversary. The last day of the year. Time to exchange places.

Linda led Cindy to her usual "slave cell" -- the shower stall in the bathroom. "Stand up," Linda said. Still not quite sure where she was, Cindy stood, and let Linda guide her through the door of the stall, and position her facing the shower head. Linda lifted Cindy's left arm above her head, and attached the wrist cuff that dangled from a chain in the ceiling, then did the same with her right arm. Then she reached inside Cindy's thong, and unhooked the clit circlet from the string that attached it to the swimsuit. Cindy's legs shook with the brief stimulation of her clit. Linda gently tugged the thong down Cindy's long, smooth legs. A tap of Linda's finger to the back of Cindy's left knee signaled Cindy to lift her foot, so Linda could pull the suit off that leg, and then a tap to her foot made the slave set her foot down again. Repeating with the right leg, Linda removed Cindy's thong, and set it aside on the counter top. A tap to the inside of each thigh signaled Cindy to shift her stance, so her legs were spread in a wide inverted "V", allowing Linda to attach the ankle cuffs to the slave's legs. Linda then walked out of the bathroom, leaving Cindy chained in the shower stall.