Yoni is doing a documentary and is asking people what they would do if they had three whishes.
Is when Yoni knocked on Sergei door and Sergei was fussing at him and didn't want him to come in.
Sergei got annoyed with Yoni and threw the stove top at him and killed him. After that he could do three whishes. First wish is to cured her sister of cancer, second wish the son of his ex-girlfriend.The third he didn't use it .Sergei didn't use it because the goldfish was his only friend.