"May I drink form it sister?" little Ivanushka asked.
"No, or you will turn into a calf," Alyonushka answered. Little Ivanushka was very thirsty, but obeyed his sister. He obeyed her again when they came to a horse's hoof filled with water. Alyonushka told him that if he drank from it, he would turn into a foal. The brother and sister walked along further, and Ivanushka became increasingly thirsty. Then they came upon a goat's hoof filled with water.
"May I drink from it?" Ivanushka asked.
Alyonushka once again was firm.
"No, if you do you will turn into a kid." But this time the boy disobeyed his sister, and upon his first sip turned into a little goat.
Alyonushka sat on the rode crying when a merchant drove by and inquired about her trouble. Alyonushka explained the situation to him, and he said that if she married him they could live happily with the goat. Alyonushka agreed, and so they lived happily this way for some time.
Then one day an evil witch tricked Alyonushka into going down to the river, where she tied a stone around her neck and threw her in. The witch then took on Alyonushka's form and lived as her for awhile. Only poor Ivanushka knew the truth about his sister. Little did he know that the witch had plans for him, too. When witch overheard him one day talking to his sister in the lake, she decided to ask the merchant to kill the little goat.
It was hard for the merchant to agree to kill Ivanushka, as he loved the goat like a person. But, being deceived by the witch, he felt his wife's wishes to be the most important. Ivanushka asked the merchant if he could go to the river for one last drink before he died, and the merchant agreed.
There at the river's edge the goat cried out to his sister, and she answered him that she couldn't help him with a stone tied around her neck. Neither the brother nor sister realized that this time a peasant had overheard their conversation, and was on his way to stop the merchant from killing Ivanushka.
Upon hearing the peasant's story, the merchant ran to the river, found Alyonushka, and took the stone from around her neck.
The witch was then tied to a horse, which was turned loose in an open field. The little goat was so happy that he turned three somersaults, and was changed back into a boy.
They lived happily ever after.