Johnny Allegro is a typical George Raft melodrama. Plot rings in a twist or two to dress up the melodrama of an ex-gangster who is trying to go straight and who takes on a dangerous assignment from the government to help prove his good intentions. From the time Raft crosses paths with Nina Foch, wife of a bigtime international agent, his fate is marked with danger.
Foch pleases in her assignment as a gal who is not all bad and only needs Raft to put her on the proper course. George Macready is the villainous husband, working with foreign powers to flood the country with counterfeit and disrupt the national economy.