This week's Number is a sexy woman about JC's age named Zoe. She's also in a similar occupation, as it turns out. She doesn't reveal her methods or sources, but she gets things done. For a fee. First, JC -- posing as her driver -- watches her give a misplaced gun back to a cop (which somehow saves another cop's career). Then she recovers some audio about an affair the CFO of a pharmaceutical company had a couple years back. But when she returns the audio to the pharmaceutical guys, they try to kill her instead of paying her. Lucky for her, JC's on it and he helps her escape. She hides out for a few days while Bench works to figure out the audio recording. They eventually find, it's not an affair at all but information about a migraine drug they're about to put on the market, which happens to kill three percent of people. When Zoe turns back up, she and JC decided to work together to take down the pharmaceutical company. They end up caught when they break in to get information, and she throws JC under the bus to get herself out. Really, though, she slips him a paperclip, which he uses to make his own escape. Then she leads him right to where she's taking the philandering pharmaceutical rep. JC gets there just in time, as Bench meets with the other head of the company and tells him they've been had. They all end up arrested. JC drives Zoe one last time, and then they bid their flirty farewells. I'm thinking this may not be the last we see of Zoe.
Meanwhile, a Fusco-less Carter works a homicide case that just happens to be the lead suspect in the 1973 murder of Marlene Elias. He also happened to have been killed with the old knife that killed Marlene (and that was stolen from lockup by JC and his gang. Since this could lead Carter to JC, she's obviously quite interested. She calls in the old cop who worked the case, but when he gets the information she needs (about Marlene's child, who ended up in the foster care system and only has one person in the world he cares about), he ends up murdered before he can share it. Lucky for Carter, she's at his apartment right after the murder, and manages to shoot at the guy who killed him. He gets away, but not before she gets him with at least one bullet, leaving some blood for her to run DNA testing on in a future episode.