In supernatural, did dean want to kill the alpha vamp?

Dean wanted to kill the head vamp. Samuel wanted to find out the location of purgatory. He was working for crowley. The cousin was either possessed or also working for Crowley Crowley is now the king of hell because lucifer is stuck in the pit. He wants to know the location of purgatory. Why I really don't know. But now we know that it was Crowley that brought back both samuel and Sam. He's holding Sam's soul hostage in order to get sam and dean to work for him.