Another entertaining--if somewhat less colorful--outing for Chicago's favorite son Jimmy Flannery, now the Democratic Party committeeman for the 27th Ward (a big promotion) and an expectant father. The mystery this time doesn't involve an actual animal: the ``pig'' of the title is a nameless, overweight fellow who drops dead--a few feet away from Jimmy--at an exercise class. A heart attack...or poison? And what's the dead man's real identity? Jimmy follows a few clues--including Italian coins and a porno magazine- -to a moderately satisfying solution...while he and pregnant wife Mary (a nurse) use their clout to help out local teenage girls with pregnancy/abortion problems. As always, narrator Jimmy is a little too good (and too Runyonesque) to be true. But fans of the series will get the usual reliable serving of charm, politics, and Chicago atmosphere: light as air--and a lot less polluted.