The first duty of Shin Bet, Israel’s feared internal intelligence service, is to be invisible. Its very motto, “Magen VeLo Yera’e,” brands this shadowy organization as the “Defender that shall not be seen.” So it is more than a bit startling to find a documentary film built around interviews with Shin Bet’s surviving directors—not one but all six: Ami Ayalon, Avi Dichter, Yuval Diskin, Carmi Gillon, Yaakov Peri and Avraham Shalom. Persuading these feared professional spooks to sit for on-camera interviews was unprecedented; extracting the details they tell, not only about their shadow war with Palestinian terrorists but their bitter conflicts with Israeli politicians, was historical and, as the story unfolds, increasingly shocking. I sat down with Dror Moreh, director of The Gatekeepers to ask him how he did it.