The Dying of the Light (2014)

Evan Lake, a desk-bound Langley CIA agent, is forced into retirement by signs of early onset dementia. At the same time he discovers his former tormentor, Jihadist Muhhamed Banir, is not dead as assumed for two decades but is alive and receiving experimental medical treatment. Banir's exact location is unknown. With the help of a disgraced young agent Evan sets out to track down Banir. He must confront him before it is too late--for both of them. Evan's search leads him from Bucharest to Mombasa where, in the guise of a doctor, he confront his nemesis.