Convincing argument

Former military policeman Jack Reacher rescues young Richard, the son of an arms dealer Zachariah Beck, from the abduction and kills a policeman who got into a conflict. In gratitude, Richard invites Jack to his home, where Beck Sr. hires him as a bodyguard. In fact, Reacher is an undercover agent who is tasked with finding the previous agent, Teresa Daniel.

Working undercover, Reacher eliminates Beck's few assistants and establishes a relationship between Beck and Francis Xavier Quinn, a former military intelligence agent who brutally mutilated and killed Jack's colleague ten years ago. Reacher supposed Quinn was dead until he saw him alive.

Richer’s connections in the outside world were federal agents Stephen Eliot, Terry Villanueva and Susan Duffy, with whom Jack had a relationship. Reacher finds that Teresa was introduced informally and finds the corpse of another girl who worked for the government. Finding Quinn and cracking down on him, Reacher looks for Teresa Daniel and hands him over to the feds.