The Assistant tells the story of Frank Alpine's journey, with aid and guidance from Morris Bober, from wannabe gangster to good human being. Frank is a mixture of bad and good, but, as the story unfolds, the mix takes in more and more good, thanks to Morris and memories of stories that Frank has heard about Saint Francis.
The variations in father-son relationships
The Assistant illustrates four classic types of father-son relationships. Sam Pearl has the "wise son," Nat, who is studying to be a lawyer, a professional son of an immigrant shopkeeper. Julius Karp has the "foolish son," Louis, who does not attempt to continue his father's business, nor move into the professions. Detective Minogue has the "wicked son," Ward, who is on the opposite side of the law from his father. He is a small-time hoodlum. Morris, who lost his own son years ago, develops a father-son relationship with Frank Alpine, an orphan. Frank fulfills the role of son by using Morris as a role model and guide, then becoming just like him.
Contrast between attainment of the American dream and success
The immigrants who populate this tale are all reaching for success in one form or another. Morris's idea of success differs from that of other immigrants, but is better than theirs.
The mood of The Assistant is bleak. Much of the time, the weather is cold. The characters are poor, except for minor character Julius Karp and Charles Sobeloff, who is barely mentioned. Another character, Nat Pearl, is headed out of poverty. But, for most of the characters, immigrants and children of immigrants, life is a daily struggle.