The Gray Man

When the CIA's most skilled operative—whom no one knows his true identity—accidentally reveals dark agency secrets, a psychopathic former colleague places a bounty on his head, sparking a global manhunt by international assassins.

Six, a highly experienced assassin in the CIA's deep-cover Sierra program, is the agency's best death trader. However, a mission goes wrong, and Six is now on the run from the CIA, pursued by psychopathic former agent Lloyd Hansen. Six must be ruthless to avoid Hansen, who will stop at nothing to bring Six down, with the help of agent Dani Miranda and handler Donald Fitzroy.

Six is a member of the CIA's Sierra program, which employs non-agents on a contract basis to carry out specific operations. When fulfilling one of these contracts, he realizes that the man he murdered was a Sierra member named Four. Four was assassinated because he had damaging information about Carmichael, a top CIA official. Six now has that knowledge, and Carmichael will go to any length to obtain it.