The Cairo slum known as Imbaba is one of the most desperately poor places on earth. Located just across the Nile from the fashionable island district of Zamalek, Imbaba is so crowded its rickety tenement buildings often collapse beneath the weight of their occupants. The alleys are unpaved, without names, and in perpetual darkness. They run with raw sewage and are choked with mounds of uncollected garbage. At night they are ruled by packs of wild dogs. The children of Imbaba wear rags, drink from cesspools, and live in fear of being eaten alive by the rats. There is little running water, only brief interludes of electricity, and even less hope. Only Islam. Radical Islam. It is written on the crumbling walls in green spray paint: ISLAM IS THE ANSWER…ONLY THE SWORD CAN SAVE US…

The mood in Imbaba that morning was more tense than usual. Riot police were roaming the alleyways and SSI men in plain clothes were surveying their surroundings from coffee shops and falafel stands. Hussein Mandali, a fourth-grade teacher at the Imbaba middle school, had seen it like this before. The security forces were about to move in for a sweep. Any man with a beard and a galabiya—or any woman in a niqab—would be arrested and thrown into the Scorpion, the dreaded facility inside Cairo’s Torah Prison complex reserved for Islamists. Everyone, regardless of sex, would spend at least a few minutes on the torture table. Pharaoh’s secret police did not concern themselves much with laws or rules of evidence. Their task was to instill fear, and they did so with ruthless efficiency.

Hussein Mandali did not wear a beard, though he did dress in the galabiya, the only garment he could afford on his pittance of a salary. Egypt’s education system, like nearly everything else in the country, was crumbling. Teachers earned nothing and students learned little. For many years the country’s twenty-five thousand public schools had been under the control of Islamists. As a result they were little more than factories that each year churned out thousands of young men and women committed to the destruction of the regime and its supporters in the West. Hussein Mandali knew this phenomenon all too well. He lectured his students daily on the rewards of jihad and martyrdom, and told them it was their sacred duty to kill Americans and Jews and topple their puppet, Hosni Mubarak. The children of Imbaba were always willing recruits. The proof of Pharaoh’s indifference to their plight was all around them.