Ra's al Ghul was Batman's Mentor. He and the Dr. Jonathan Crane/Scarecrow attempted to release Scarecrow's fear toxin into Gotham's sewers, but James Gordon and Batman stopped them. Gordon damaged some train tracks that were part of the tracks that the train with the fear toxin was on,and moments before it went off the tracks and crashed and exploded in a car garage, Batman said to Ra's: I won't kill you, but I don't have to save you. Ra's used his last moment to meditate. It is unknown if he survived the crash.