Back at the detail office, a laptop screen displays the number on D'Angelo's pager: 1429964-13. Lester comments that "142 isn't a working telephone exchange. To Daniels, sitting at the computer with him, Lester observes, "Six intercepts so far, and five aren't working numbers?" Daniels wonders if something's wrong with the recorder, but Lester says, "We're getting what you'd expect -- seven digits of a telephone number -- and a two-digit add-on to identify the caller, like here -- 13." Oh, seven-digit local dialing. How I miss you. Prez appears to say that McNulty's calling, and Lester picks up. We barely hear McNulty ask if Lester got a "142" exchange, and Lester confirms that he did. McNulty finds that "fucked up," and they hang up. Sanding a piece of dollhouse furniture (a desk, perhaps?), Lester explains to Daniels that McNulty's getting the same information on the pager itself, so the issue isn't with the recorder. "These mopes are using a code to cover their calls?" Daniels marvels. "Uh-huh," drawls Lester. Daniels says that it's pretty sophisticated. "What is?" asks Prez, tentatively. Lester explains that the Barksdalies have coded the telephone numbers in their pager messages. Prez asks how they know, and Daniels explains how the software works, and that the information on the computers is what they'll use in court, along with the pen registers. Of the latter, Lester exposits that every time anyone uses a pay phone in the low-rises, the recorder returns the number dialed, the time the call was placed, and the duration of the call. "Incoming calls too," Daniels adds. "Spy shit," says Prez, dopily. "Very cool." Prez asks again about the code, and Lester says that they have to be using one, because the numbers don't make sense otherwise. Touch tone music? No?