"Well, actually, it's the Packer's Inn, Forty-seventh and Ashland. Right in the middle of the Stockyards and all—"
* * * * * * * * * *
The Professor still thinks he's having a discussion with a peer and an equal. As if Scarsdale expected an answer to his question. As if Scarsdale had any idea, or even cared, about Heino's accommodations. He just wanted to let Heino know that Scarsdale knew he was staying at a shabby hotel. Heino, not picking up on this, simply clarifies the point by admitting the location of his current domicile is in the middle of The Stockyards. Heino says this without shame because he doesn't realize the game Scarsdale is playing. Just as I wouldn't!
This sentence ends in an em dash because Heino is being interrupted by Scarsdale (or some other jerk rich guy in the dark room). Because, remember, Scarsdale wasn't actually asking the question in the expectation of an answer. He's simply controlling and manipulating the space to exert his power.