Underworld opens with a series of title cards setting its mood, telling of "a great city in the dead of night...streets lonely...moon clouded...buildings as empty as the cave dwellings of a forgotten age." Suddenly an explosion shatters the façade of a bank building, and the title cards announce that crime kingpin Bull Weed (George Bancroft) has "closed another account." Bull emerges from the wreckage carrying his swag, but while making his getaway, he spots a derelict (Clive Brook) wandering past, a potential witness, despite his apparent inebriated state. Instead of killing him, Weed knocks him cold, throws him in his car, and takes off, intending to figure out later what to do with his unexpected "guest." Weed turns out to be a man of many parts -- greedy and a brute when it comes to getting or keeping what he wants, but with a soft spot for the underdog, and also smart enough to recognize the importance of some knowledge that he doesn't possess. He takes a liking to the erudite but totally dissolute man, christening him "Rolls Royce" and keeping him around as an elegant stooge, advisor, and sometime driver. The man is only too happy to be taken off the streets and set up in an apartment with a full library of books at his disposal, and the two men's relationship is harmonious and mutually beneficial -- the former derelict has a home, and the crime boss gets smart advice.
Bull Weed and Rolls Royce's meeting is our introduction to the world of Weed, in which he runs much of what he surveys, but not without challengers. His most notable rival is vicious hood "Buck" Mulligan (Fred Kohler), who doesn't like Weed and also covets his girlfriend, "Feathers" McCoy (Evelyn Brent). Rolls Royce is also drawn to Feathers, who is, in turn, attracted to the gentle, witty man; however, out of decency to Bull, who has been a benefactor in his own way to both of them, they agree to stay away from each other. This drives Rolls Royce back to the bottle part of the time. Weed and Mulligan finally have it out during the underworld's annual drunken bacchanal, a wildly expressionistic sequence that must have seemed all the more dazzling and compelling to audiences in 1927, in the middle of the Prohibition Era. Mulligan tries to take advantage of his rival's passing out in a stupor by having his way with Feathers, but Bull awakens with help from Mulligan's jealous girlfriend and Rolls Royce, and proceeds to rescue Feathers and finish Mulligan -- an act that gets him charged with murder, convicted, and sentenced to die. Feathers and Rolls Royce, with the help of Bull's gang, try to help him break out on the eve of his execution, but their plan fails. Bull manages to escape on his own, though, and goes seeking revenge against Feathers and Rolls Royce, whom he believes have betrayed him. Just as Bull is about to pull out his gun, however, he discovers that Feathers and Rolls Royce had always played it straight with him, and even if they are attracted to each other, they never did anything about it, out of respect for him. He lets them go and surrenders to the police. Admonished by the head of the arresting squad that his break only gained him two hours, he smiles, saying those two hours were worth it for what he found out.
A masterpiece of the silent era that still holds up as an exciting and engrossing movie over 70 years later, and which is properly regarded as the first modern American gangster movie, Underworld has elements that anticipate such sound classics as Little Caesar and The Public Enemy, and a final shoot-out similar to those in Angels With Dirty Faces (co-starring Bancroft) and Each Dawn I Die. Director Josef von Sternberg and cinematographer Bert Glennon actually manage to convey sound with pure visuals in the suspenseful jailbreak scene, and, overall, they produced a beautifully stylized film, visually expressionistic but sentimental in tone and story. The script, by Ben Hecht -- a veteran Chicago reporter -- also crawls with allusions to real-life figures, Bull Weed being a highly sanitized stand-in for Al Capone, and "Buck" Mulligan a composite of Capone's Northside mob rival Dion O'Bannion and his eventual successor, O'Bannion gang member George "Bugs" Moran.