Rabbi Aba tells how people can take a scroll of Torah to the grave sites of righteous men, which awakens their souls, and the dead then realize that the world is in distress but there is no one who knows how to inform the dead about the problem. The rabbis talk about the importance of repentance and fasting, and about how critical it is to never change a single letter of the Torah. They say that when there are no more righteous men in the world, the world will survive only by the merits of the deceased. We learn that when a righteous person leaves this world he is then found in all three worlds, Briyah, Yetzirah and Asiyah. He shields the world during his lifetime and even more after death.