Batman (1940) #671
"The Resurrection of Ra's al Ghul Part 4: He Who is Master" is written by Grant Morrison and drawn by Tony Daniel. Batman and the international crime boss Ra's al Ghul form an uneasy alliance after the villain threatens the lives of Robin and Batman's son (his own grandson), Damian. Their goal is to reach the hidden city of Nanda Parbat, where the waters that feed the world's wondrous Lazarus Pits emanate.
However, the city is already under siege by the Sensei, the martial arts master who is Ra's al Ghul's father, and the man who claims he's saving the honor of the much-feared League of Assassins. Ra's al Ghul is seeking the waters to restore his current body which has been poisoned by Polonium. Batman is there to stop either madman from gaining the power they seek to expand their criminal empires. But not even the Dark Knight is match for the Sensei's mastery of combat tactics and Ra's al Ghul proves he's not worthy of trust!