Two sisters.

The girl who had just passed through the mirror was scared and confused.
Ruth reached out to touch her, but the twin looked at her in horror and headed towards the ladder. She couldn’t run very fast, as her left foot was deformed.
“Wait!” Shouted Ruth, grabbing her arm.
“Don’t be afraid”. She then pressed her right hand on her own foot and her left hand on her twin’s club foot, “I can help you”, and in a matter of seconds the deformity was gone.
“Oh I see you’ve already met each other!”, said Mother as she entered the attic. “You must be Clara!”.

Despite a striking physical resemblance, Clara was the opposite of Ruth, extremely obedient and well behaved. Even her powers were different.
Each night she would hear whispers in her head and every now and then she would freeze completely as her eyes rolled back.
Mother would take her hand:”It’s alright darling, what do you see?”. As the years passed it became blatantly obvious which of the girls held a special place in her heart.
Yet Clara looked up to Ruth, who didn’t waste the chance to boss her around.
After every lesson, if the girls had done well, Mother would give each of them a chocolate cookie.
One day Ruth made a suggestion, instead of eating the cookies immediately, they should put them in a metal box in the attic and once the box would be full, they would have a tea party.
Clara wasn’t convinced, as she could sense Ruth’s real intentions, but she had felt in debt towards her ever since her foot had been cured, so she agreed.

After two weeks the box was almost full and in the silence of a winter night, Ruth climbed up to the attic to claim her prize.
But to her disbelief, the box was empty!
She ran downstairs and pulled her twin out of bed: “You traitor!”
Clara couldn’t understand what was happening as Ruth dragged her up to the attic to show her the empty box.
“I gave you the power to run, you ungrateful witch, and this is how you repay me?”, yelled Ruth, furious.
“It wasn’t me”, replied Clara.
“I don’t believe you!”
“I swear, I didn’t do it”, cried Clara, then all of a sudden she froze and her eyes rolled back.
“There’s someone in here”, she muttered as she reached out her hand and touched the wall.
The bricks started to move and change color, the outline of a figure started to appear.
Ruth grabbed it by the neck and shouted: “Show yourself or I’ll turn your throat into an elbow, you thief!”
Like a chameleon the figure changed color completely and a boy emerged from the wall.
Ruth and him locked eyes for a moment before she let go.
“What’s all this noise”, yelled Mother as she climbed upstairs. “Oh Boris, there you are! I’ve been looking for you for days”.