When Sam does return home, Jessica dies when she is pyrokinetically set on fire by Brady, who is hidden from sight to keep his hand in her death a secret. Brady later confirms that Azazel had ordered him to kill Jessica. he eventually discovers that the truth and kills Brady to finally avenge Jessica.
Azazel orders the assassination of Sam's girlfriend Jessica Moore, who was a distraction. Her death prompts Sam to return to hunting. Demons cannot be killed by conventional means so the Winchesters track down the Colt a mystic gun capable of killing anything in "Dead Man's Blood".
