For decades, Ayatollah Ali Khamenei ruled Iran with an iron fist—building a parallel army, funneling billions into a regional axis of terror, and obsessively pursuing the destruction of Israel. But now, at 86, the once-feared leader appears frail and defeated. His life's work is unraveling, and the Islamic Republic is already searching for his successor. What led to the fall of one of the Middle East’s most powerful and dangerous figures?