Bob Woodward, to write his poignant non-fiction book, interviewed 250 former and current CIA employees and used many intelligence agency documents that were only recently declassified. Among the interviewees was former CIA Director Casey. The last interview took place in the hospital a few days before his death. According to Woodward, Casey knew about his imminent death and was extremely frank. The book talks about the covert operations of the CIA and other US secret services.