Savvy, dedicated and hard-nosed, Jack’s boss is a hot-head whose personal demons have wrecked his family life and derailed his work as a legendary CIA operative. Demoted to a desk job, Greer is eager to get back to the front lines in the War on Terror.
Greer is the new head of Terror, Finance, and Arms Division (T-FAD). He was demoted from working in Karachi after having killed an asset who was going to have him tortured. He helps Jack Ryan on his search for Suleiman. Together they travel to Yemen and Paris on the hunt for this new terrorist. He helped Jack save Hanin from Yazid. When they realized that Suleiman was using American hostages as carriers for Ebola, the President was confined to Washington Memorial Hospital. Greer turned the car around and headed for the hospital after Jack realized that Suleiman was planning another attack there. He helped search the hospital for Suleiman and saved Cathy's life by killing Dudayev in the elevator. He was promoted to deputy station chief in Moscow for having helped foil the terrorist attack.