The trail will lead him through layers of conspiracy to a vicious Russian mercenary, Leonid Arkadin, who was also a graduate of the Central Intelligence training program Treadstone. A covert course designed to create ruthless assassins for C.I., it was shuttered by Congress for corruption. Yet before it was dismantled, it produced Bourne and Arkadin, giving them equal skills, equal force, and equal cunning.

As Bourne's destiny circles closer to Arkadin's, it becomes clear that the eventual collision of these men is not of their own making. Someone else has been watching and manipulating them. Someone who wants to know, Who is the more deadly agent?