Reese, Finch, and Shaw work to save the life of a sailor named Jack Salazar who is inadvertently caught up in a diamond smuggling operation run by a team of Force Recon Marines. Shaw gets used to being a member of the team, although her propensity for violent solutions worries Finch.

Wayne Kruger is the owner of a company known as Lifetrace, which specializes in revealing members’ privacy on their profile pages and selling it to various organizations. Reese, Finch, and Shaw monitor Kruger’s activities in the company, which is currently making a deal with another large retail company called Riverton.

When the Machine gives the number of Ian Murphy , a man suspected of being a stalker, Reese along with Shaw recruits Carter, Fusco and Zoe to investigate further into his background.

Person of Interest S03E04, Reese and Finch’s next number is that of Vanessa Watkins , a prominent New York prosecutor who is accused of killing her defense attorney husband, Jeremy. The police find a gun with her DNA on it and arrest her.

In a series of flashbacks to Shaw’s childhood it is revealed she was in a car with her father when he was killed in a wreck, but that she showed a shocking lack of emotion over it. In the present, after Shaw saves another number, Finch begins expressing concern about Shaw’s callous treatment of them. […]

While Shaw is abducted by Root, Finch and Reese get the number of Timothy Sloan , an estate investigator. Finch goes undercover as Sloan’s assistant while Reese continues investigating Shaw’s whereabouts.