Leaving the words, "I'll be killed by the black dog!" behind, an architect jumps off his own mansion and dies. Sam and Dean think that it's possible that it's the work of their old demon enemy and start investigating the truth. They learn that 10 years ago, other geniuses died in similar ways. Sam and Dean think that the "Crossroads Demon", who grants people's wishes in exchange for their lives, is behind the case. In order to save the next victim, they take a big gamble and risk their own lives.