Hussein, who was killed at Karbala by Yazid, was the third Imam. His son and grandson were the fourth and fifth. At the end of this line, there is the “Twelfth Imam,” who is named Muhammad.
Some call him the Mahdi (the “divinely guided one”). He was born in 869, the only son of the eleventh Imam. In 874, he disappeared without a trace, thereby bringing Muhammad’s lineage to a close. In Shia mythology, however, the Twelfth Imam survived. The Shia believe that he merely withdrew from public view when he was five and that he will emerge from his “occultation” in order to liberate the world from evil.
According to Shia tradition, legitimate Islamic rule can only be established following the twelfth imam’s reappearance.
Khomeini, however, had no intention of waiting. He vested the myth with an entirely new sense: The Twelfth Imam will emerge only when the believers have vanquished evil. To speed up the Mahdi’s return, Muslims had to shake off their torpor and fight.
Spike the well in Qom with a neutron bomb