Prudence Penny, the New York Mirror's cooking columnist, was teaching readers how to make rum pie with zwieback crust. "Break up zwieback," commanded Prudence conventionally. The next step in the recipe was the kicker: "Keep rum bottle handy; if smashing up zwieback exhausts you, take swig of rum and resume zwieback breaking when strength returns." The extraordinary advice may have startled housewives not yet privy to the Mirror's secret: Prudence Penny is a onetime police reporter named Hyman Goldberg.
Since June, when he took over the column after the death of Vaudine...