Writer-narrator Bagby is on his way to meet country-western star Shad McGee (who's concertizing in N.Y. and wants a ghost-writer for his memoirs) when somebody pushes old George onto the subway tracks. And as soon as Geo. gets out of the hospital, he's attacked again--by a Stetson-hatted auto assassin in a lethal Lincoln. . . which happens to belong to Shad McGee! So GB and Inspector Schmidt gather together the McGees (pneumatic, bejeweled mistress Lucinda Belle; downtrodden, seething son Beau; swaggering Shad himself)--and, after a mess of collard greens, the questioning begins. . . but goes nowhere. Then Lucinda Belle is shot, and Shad is stabbed backstage. Whodunit? And how do these deaths connect to the attempts on GB? The puzzle is strictly third-rate; the pacing is erratic, with lots of recapping chatter. But ""Bagby"" gets some so-so laughs out of the stereotyped C-W milieu, making this pleasantly middling work from the prolific Aaron Marc Stein.