We're getting closer to finding out what's going on with Ralph, who is now groggy and lying at the bottom of a pit or a well because we only have flash back ten hours...
...to the sheriff's office, where Ralph is moping about having killed Nathan, with Jack consoling him by telling him, essentially, that Nathan asked for it, and then the two of them joke about brothers getting their siblings in trouble. They get the news that Russ's car has been found outside Phoenix, which likely means he has fled the state if not the country.
Katherine breezes in, letting Ralph know that she's got new info on Diane Desmond. Her CI thinks she was given a hot dose of heroin, possibly because the mob thought she was working for the feds. Turns out Ralph doesn't know who the CI, which isn't a surprise, but Katherine is also cagey with him on whether Diane was an informant, which kinda is. She thinks there's enough there to get the DA to sign off on some wiretapping of Rizzo, Savino (I think Laura wouldn't be pleased to hear that), the whole crew. If the DA says yes to the wiretap, Katherine says as she heads out, she'll be celebrating with a drink tonight, and she doesn't want to do it alone. Ralph, she can only throw herself at you so many times before she'll leave you alone.
Over at the Savoy, Mia destroys Jack's ego by explaining that Harwood didn't just suddenly start losing, but he must have realized they were on to him and decided to throw the game. But he lost too well and wins too easily, so Mia figures he does have a spotter, and that's why she and Jack enter the hotel room right above the game. There's a guy in there, sticking a kind of periscope into spots on the floor, through which he can see the other players' hands, and relaying the info through a signaling device. He's so preoccupied that he doesn't even notice Mia and Jack come in at first.
So it's back downstairs to the poker game, Mia holding the signaling device behind her back and pressing it randomly, throwing Whitford off his game until he gets up from the table, making it easier for Jack to stop him and whip open his shirt to reveal the receiver.
Over at the sheriff's office now, Jack explicitly explaining the plan for any viewer who hasn't caught on. Whitford admits to having cheated the one time, which is a misdemeanor, so he's not pleased to find out the police confiscated the $150,000 they found in his hotel room safe, which will be held at the Vegas Bank and Trust (which should set off alarm bells for anyone watching at the start of the episode) to be used as evidence in his upcoming trial.