Extended intro of surveillance cameras with Finch voiceover fills us in on everything: "You are being watched. The government has a secret system, a Machine, that spies on you every hour of every day. I know because I built it. I designed the Machine to detect acts of terror, but it sees everything: violent crimes involving ordinary people, people like you. Crimes the government considered irrelevant. They wouldn't act, so I decided I would. But I needed a partner, someone with the skills to intervene. Hunted by the authorities, we work in secret. You'll never find us. But, victim or perpetrator, if your number's up, we'll find you." Okay, so that intro's a little cheesy, but I guess it's necessary for a sort-of (or mostly) procedural, for those audience members that come and go on a given week.
We open with surveillance footage of a guy with flowers arranging to see someone at their place. He gets in an elevator, then JC sneaks in and says he "almost missed it." He grills the guy about whether the flowers are for his wife. He lies that they are, but JC knows better and tells him to come clean about the cheating. The guy gets defensive, until JC saves the guy's life from the two guys in the elevator who the cheater's wife hired to kill him. And by "saves the guy's life," I mean that JC shoots both guys. It doesn't show for certain whether he kills them, and they're groaning a bit as he leaves the cheater with advice to call the police "and a good divorce lawyer." So hopefully he didn't kill the two hitmen just to save one cheater. Two for one is only a good deal if the person you're saving is a child or at least a good person.
Surveillance footage cuts to a guy being offered "triple his usual fee" for a job. Then Finch calls JC, who's across the street, watching Finch walk. He fills him in on his latest salvation, and then tells Finch that he's doing "a little research." Finch is interested in hearing about it later - though I'm guessing JC won't tell him it's Finch he's researching. Finch wants to meet later for a "somewhat unusual" number that's come up, he says, then disappears around a corner. When JC gets there, Finch really has disappeared (along with everyone else on the streets of New York; apparently they found the one street in the city where there's no one milling around), and he tells JC to remember that they meet on Finch's schedule, not JC's.
Carter shows up at the elevator crime scene and, since she's homicide, the detective on scene isn't sure why she's there. She says it's part of an ongoing obsession she has. Actually, she says it's an investigation, but my hunch is she's already way off the books with this JC thing. The detective tells Carter what happened: These two guys tried to kill a rich guy, who says a guy in a suit "intervened."