Sam and Dean race to Bobby's side after he lapses into a coma and can't be awakened. While unconscious, Bobby battles his personal demons and the reason he became a hunter is revealed. Sam and Dean discover someone poisoned Bobby with a potion that will kill him if he doesn't wake soon. When the brothers decide to take the potion themselves to enter Bobby's dream in order to save him, they come face to face with their own personal nightmares.