Garfield's opening voiceover suggests his guiltless, matter-of-fact involvement in the enterprise: "Tomorrow, July 4th, I intended to make my first million," but Polonsky's mise-en-scene troubles the confidence. A quick tilt down and swish pan shows spots of people moving along Wall Street. Polonsky's visuals suggest that Morse and Tucker's success in business is contingent upon their ability to aggressively crush others.

Garfield seems unconcerned about this, but when he fears that his brother Leo (Thomas Gomez), a small numbers banker, will also get destroyed in the scheme, he jeopardizes his success in order to bring him in on the deal. He wants to protect Leo's small business, to pay him back for putting him through college. Leo is not gracious about the opportunity. He calls Joe a "gangster" and shouts "my own brother blackmailing me." Joe is alarmed and embarrassed, but his attempts to save his brother help bring about his redemption.

Following Leo's rejection, Garfield emotes one of cinema's great meditations on guilt. In a two shot, he stops his playful conversation with Doris Lowry (Beatrice Pearson) for one of serious angst. His face no longer looks brightly outward but inward with distraction. His poetically paralleled language elides his identity with his brother's, creating a noir distortion, a weird sense of connectedness. To give and not want anything back, he claims is "perversion." "To reach out, to take it, that's human, that's natural. But to get your pleasure from not taking. From cheating yourself deliberately like my brother did today, from not getting, from not taking. Don't you see what a black thing that is for a man to do? How it is to hate yourself, your brother, to make him feel that he's guilty, that I'm guilty. Just to live and be guilty." Joe's trailing words mirror his central dilemma. He may be willing to take risks in Tucker's enterprise, but as his last name suggests, (re)Morse, and his self-absorbed repetition of "guilty," he's a man of conscience, who vainly tries to hide behind a street-smart sense of Social Darwinism.

Eventually Joe forces Leo in on the scheme, but he can't save him. Doris speaks the film's noirish fatalism: "Oh, you'll make him rich, in his death," she says, angrily from inside a phone booth. As the film's moral center, she's right. The whole "Tucker business," the money-making scheme, alienates workers from their work and each other. One of the disconsolate workers, Bauer, stools to the cops and eventually betrays Leo to Tucker's rival, Ficco. Leo's death is placed by Polonsky and screenwriter Ira Wolfert in a social context. Unlike other noirs, Force of Evil blames institutions (Wall Street) and the pursuit of monopoly capital for dehumanizing and destroying people.

Doris, too, is nearly destroyed by the darkness of business, the desire for the "ruby" of money. Newcomer Beatrice Pearson plays her character in a naive, ingenue way, and represents the force of evil within us all. As a young worker at Leo's bank, she denies her own guilt in the shady business, but when quick-talking Garfield accuses her of being in on a "Policy" racket that takes nickels from hard-working folks who should be paying their weekly insurance premiums, she quits. Morse's words make her realize the truth, but she gets too comfortable in her easy transition to knowledge, and assumes, through the power of quitting, that she understands more than she does. He later asks her out, buys her flowers and offers her a metaphorical "ruby." She finally accepts his attractive wickedness and tries to work from within it, being neither naive or judgmental. At the night club, she confesses her redemptive love, "Oh, Joe, I don't want this money. Nobody wants it. I want to somehow to get you, Joe, to save you for yourself and myself. Somehow you're wild and crazy and stuck in a trap and somehow you won't fight to get out," she pauses, grabbing his face, the repetition of "somehow" suggesting the chaotic randomness of their love. "And somehow I love you." She kisses him and helps move the tarnished hero towards grace.