It is nighttime in the prison at Blackwell's Island. The cellblock is lit by one electric bulb that sheds light on Yank in his cell. Yank is seated in the position of Rodin's "The Thinker." Yank's face is covered with bruises from the police officer's clubs and a bandage, soaked with blood, is wrapped around his head. Suddenly, he reaches out and violently shakes the bars to his cage, "steel," he says to himself, "Dis is de Zoo, huh?" Laughter echoes through the cellblock from other inmates. Conversation is heard among the inmates in reaction to Yank. They tell him that the jail is an old iron house. Yank tells the men he thought he was in a cage at the zoo. The men tell him he is certainly in a cage, but not at the zoo. The men and ask him to tell them why he is in jail. Yank dully begins his tale of being a fireman, but then in a sudden rage exclaims them he is a hairy ape. As he shakes his bars, Yank tells the men he will hurt them if they kid him. He asks them if they're apes as well. The men don't act favorably to this idea and yell threats back at Yank. The men tell Yank to be quiet so the guard does not come. Delusional, Yank corrects them, saying that they must mean the Zookeeper, not the guard.
After Yank calms down, he finally tells the men why he was put in jail. Yank describes Mildred in the stokehole dressed in white and how he thought she was a ghost. Yank depicts Mildred as a dead thing the cat brought in that belonged in the window of a toy store or in a garbage can. The men ask what the girl's name was. After disclosing Mildred's last name the men tell Yank she must be the daughter of Douglas, the president of Steel Trust.
A man tells Yank he should join the Wobblies if he wants to bring down Steel Trust. The same man reads an excerpt from the Sunday Times about the Wobblies excerpted from a speech by Senator Queen. The speech describes the "menacing" Wobblies; the Industrial Workers of the World Senator Queen renames the "Industrial Wreckers of the World." Yank is fascinated by the wobblies, in Senator Queen's words the "foul ulcer on the fair body of our Democracy—." At an especially patriotic point in the speech, Hisses and catcalls erupt from the cell block and the men mockingly yell out patriotic slogans, "justice! honor!..Opportunity! Brotherhood!" Their cries dissolve into a unison, surrendering exclamation, "ah hell." A voice calls for the men to give the Queen Senator "a bark" and a chorus of barking and yapping sounds in the block. The voice continues to read the senator's speech that describes the Wobblies as the force that would tear down society and put the lowest scum in seats of power, turning the world the civilized world to "topsy-turvy" and degenerate man back to the ape.
Yank is given the paper to read for himself. Again, he molds in the form of Rodin's "The Thinker." With a furious groan, Yank leaps to his feat, suddenly realizing that Mildred's father makes steel—the steel that he thought he belonged to. Yank shakes his cage, crying out that Mildred's father made his cage, but he will drive through and destroy it. While bracing his feet against the other bars, Yank seizes a bar and wrenches it backward. Under his strength, the bar actually bends back. The guard rushes in as Yank bends another bar. To restrain Yank, the Guard shoots a powerful stream of water at him as the guard calls for backup and a straightjacket.
Scene Six is a brief sermon, a short history lesson on the Wobblies, also called The Industrial Workers of the World. For Yank, a workers union spells hope, it brings the possibility of "belonging" and turning the societal power structure in his favor. The I.W.W. was quite active when The Hairy Ape was written. Undoubtedly O'Neill was influenced by their mandate, "The working class and the employing class have nothing in common. There can be no peace so long as hunger and want are found among millions of working people and the few, who make up the employing class, have all the good things of life."
The Hairy Ape makes clear distinctions between the "employing class" and the "working class." Yank, as exemplified in Scene five, understands these differences quite specifically. What Yank wants, however, is not the same as what the I.W.W. has historically striven to achieve. As explained in Scene seven, the I.W.W. promotes "Direct Action." Direct Action is defined as, "Industrial action directly by, for, and of the workers themselves, without the treacherous aid of labor misleaders or scheming politicians. A strike that is initiated, controlled, and settled by the workers directly affected is direct action. Direct action is industrial democracy."
For Yank, "Direct Action" is impossible because he has no relationship or communication with his superiors. The whistle-blower that commands the workers to keep moving is hidden in darkness above the stokehole and the Engineers that escort Mildred have no verbal communication with Yank. Authority on board the Ocean Liner is faceless and nameless—not a negotiable or, in the case of the whistle-blower, even a human presence.
As is apparent in Scene seven, Yank does not understand the concept of "direct action." He wants to join the I.W.W. because he thinks they use destructive means to gain worker rights. Senator Queen's speech, read from a paper by one of his inmates, characterizes the group as dangerous, forceful and explosive—all attractive to Yank. Queen describes them as an "ever-present dagger pointed at the heart of the greatest nation the world has ever known" and the "International Wreckers of the World." Yank also feels a special kinship to the Wobblies because Senator Queen remarks that the group would degenerate modern American society "back to the ape."
Yank transitions from the "ape" to the "thinker" in Scene Six. After he hears that the Wobblies described as making men like apes, men like him, he takes the paper and sits in the "attitude of Rodin's 'The Thinker.'" As Yank sits there he suddenly jumps up as if "some appalling thought had crushed on him." Yank rejects his identity as an "ape." This is a major change from the beginning of the scene where he identifies himself to the other inmates as the "ape" and thinks he is in a Zoo. Yank realizes that he is not an ape, but a person caged and imprisoned into a social identity by companies like Steel Trust. While this thought makes Yank realize he is not a wild animal it inspires him to act like one, and bend back the bars of his cage.