Sidney Falco impatiently buys a copy of a New York newspaper just to read JJ Hunsecker's column. He throws it away when he finds once again that his clients are not getting any press. Publicity agent Sidney's clients are angry. JJ's angry that Sidney has failed to break up a romance between his sister Susie and jazz guitarist Steve Dallas. Sidney tells his secretary that JJ is his golden ladder.
Sidney visits the club where Steve plays with his band. Cigarette girl Rita tries to ask Sidney for help but he walks off as she says she's "in trou-." Sidney's such a good friend. Sidney's uncle Frank manages Steve and tells Sidney the romance has ended. Sidney barges in as Susie accepts Steve's marriage proposal. Steve's pissed that Sidney's snooping on him. I'm pissed that all the characters' names begin with "S." Sidney denies snooping and accuses Steve of being ungrateful for the publicity he's gotten Steve. What publicity?
Rita tells Sidney her woes as he half-listens. Because he has a half-brain. Rita's being fired because she wouldn't have sex with newspaper columnist Leo Botha. Sidney takes Susie home and lies (again) that he dislikes Steve (because JJ told him to) because Steve thinks JJ is a controlling monster. Susie says JJ makes Sidney jump through hoops like a poodle and Sidney acts outraged. The key word is "acts." Susie tells Sidney of her marriage plans.
Naturally Sidney scurries to tell JJ, who's holding court at 21. That must be a restaurant in New York. JJ treats everyone as a minion, even the senator at his table. JJ chastises the senator for publicly appearing with the blond "aspiring singer" and her "manager." Aspiring singer means mistress and manager means pimp. This fifties slang is harder than I thought! JJ walks out gloating over scolding the senator. "Senator" means idiot. Some things never change. Not yet satisfied, JJ lords it over brutish cop Harry Kello. JJ is not pleased to hear about Susie and Steve but Sidney has a plan.
Sidney asks creepy columnist Leo Botha to print a smear about Steve or he'll tell Mrs. Botha of Leo trying to have sex with Rita. Leo says Sidney has "the scruples of a guinea hen and the morals of a gangster." Leo refuses and confesses to his wife before Sidney can. Sidney tells newspaper columnist Otis Elwell about his trouble with JJ and says JJ has "the scruples of a guinea hen and the morals of a gangster." Sidney can't even come up with an original insult for JJ. Otis will print the smear if Sidney can find him a woman.
Sidney brings Otis to meet Rita. Sidney tells Rita that Otis will help her keep her job. Rita is outraged she's being pimped. Sidney acts outraged that Rita is ungrateful for his favour to her. Have I mentioned yet how evil Sidney is? Rita stays with Otis as Sidney leaves to call JJ.
In his column, Otis accuses Steve of being a pot-smoking Communist. Sidney snoops around JJ's office and finds an advance item about comedian Herbie Temple. The comedian and his manager don't want to do business with Sidney. They must know him. Sidney picks a fight with the manager and pretends to phone JJ and "dictate" the advance item he just read in JJ's column. I hate Sidney. I hate him.
Frank and Steve are furious at Sidney. Steve's been fired. Sidney yells at them for (rightly) accusing him. Sidney yells at his ashamed secretary that this is real life. I hate Sidney. I hate him.
Susie asks JJ to get Steve his job back, which he does. She brings Steve with her to meet JJ but JJ and Steve argue. Steve asks Susie to stand up for herself to JJ but she runs away. JJ asks Susie to break up with Steve and she agrees.
Still not satisfied, JJ wants Steve destroyed. Literally. JJ tells Sidney to sic Kello the cop on Steve. Sidney is horrified and refuses. That's a twist. JJ offers Sidney his column when he vacations with Susie and Sidney agrees. Sidney plants drugs on Steve and Kello beats him up. Steve that is, not Sidney. I wish.
Sidney celebrates "success" at a club. Herbie Temple asks Sidney to represent him, but Sidney brushes him off. Have I mentioned evil yet? Sidney gets a message from JJ and goes to JJ's apartment, only to find Susie. She's just returned from Steve's hospital and accuses Sidney and JJ of masterminding the assault. Susie tries to commit suicide by leaping off the balcony but Sidney catches her. JJ walks in to find Sidney leaning over crying Susie. Things look bad for Sidney. Finally! Sidney begs Susie to tell a furious JJ about her suicide attempt but she stays silent. JJ slaps Sidney around and Sidney reveals that he and JJ are responsible for Steve's injuries. Sidney runs away as JJ sends Kello after him. Susie walks out on JJ. The cops pick up Sidney. Unfortunately, the view of Kello beating up Sidney is eclipsed by some other cop who stands in the way. Susie crosses the street into daylight. It's a new day, geddit?