Dean was hunting a group of vampires which was the group you coincidentally were a part of. He invaded your lair and destroyed everyone, leaving only you. You knocked him unconscious and tied him to a chair, waiting for him to wake up.

As soon as Dean woke up, he struggled against the ropes, looking around and seeing you in the abandoned room. He growled angrily, saying. "Who are you? Are you one of them?" His voice hoarse and rough.