9/11 had a huge impact on the show. It was nine days before the intended start of the series, an episode which involved stopping a terrorist strike masterminded by one Osama bin Laden. That episode was shuffled to later in the season, along with one involving an anthrax scare after several real-world anthrax attacks. The show was retooled, involving a major shakeup at the top of the Agency, to focus more heavily on the CIA's role in The War on Terror.
Lots of Espionage Tropes, naturally.
This series provides examples of:
- The Con: The agents sometimes use techniques lifted straight from Con Artists to get their objectives accomplished.
- Flock of Wolves: A sting operation to catch terrorists nets them agents from the FBI, Immigration, and the Secret Service, but no actual terrorists.
- The Mole: One episode focused on the search for one.
- Overt Operative: Some of the characters are overt employees, and thus don't have covers.
- Spy Glasses: With infrared camera.