A month has gone by and Yank has finally been released from prison. Yank stands outside an International Workers of the World office near the local waterfront. Inside the I.W.W. office sits the Secretary putting entries in a large ledger. Yank knocks on the door of the office as if he were entering a secret club. Receiving no answer, he knocks again, this time louder. The Secretary shouts that he should just come in. The men in the room look over Yank who enters the room suspiciously. Yank tells the Secretary that he wants to join the I.W.W. The Secretary is satisfied to hear that Yank is a fireman, as not many have joined. Yank agrees, he tells the Secretary that the firemen are dead to the world. The Secretary makes out a membership card for Bob Smith, Yank's real name, and tells Yank membership will cost him half a dollar. Surprised at how easy it was to join, Yank hands the Secretary the change. The Secretary tells Yank to look at some of the literature on the table and tell the men on his ship about what the I.W.W. are doing.
The Secretary asks Yank why he knocked. Yank responds that he thought they would need to check him out to know if he was safe to let in. The Secretary assures Yank that the I.W.W. is above board and does not break any laws. Yank, thinking the Secretary is just trying to test him, gives the Secretary a knowing wink. Yank assures the Secretary that he belongs to the group and he will "shoot de woiks for youse." Yank assures the Secretary that after he is initiated into the group he will show how he belongs to the group. The Secretary again tells Yank the I.W.W. has no secrets and cautiously asks him if he thinks social change should be enacted by legitimate direct action or by dynamite. Yank enthusiastically replies, "Dynamite!" Yank discloses to the Secretary that he wants to blow up Steel Trust, blow up all the steel in the world and then send Mildred a letter, signed the "Hairy Ape."
The Secretary backs away from Yank and gives a signal for the men to search Yank for weapons. The Secretary comes up to Yank and laughs in his face. The Secretary accuses Yank of working for the government, he tells Yank he is the biggest joke they have dealt with yet and calls Yank a brainless ape. The Secretary then instructs the men to throw Yank out. Landing in the street he is confused and pathetic. Brooding, he once again takes the form of Rodin's "The Thinker." Yank describes himself as a busted Ingersoll—he was steel and he owned the world and now steel owns him. Yank asks to the man in the moon for the answer. A policeman tells Yank to move along. Yank asks where he should go and the Policeman tells him "hell."
It is twilight of the next day and Yank looks in on the monkey house at the Zoo. The ape inside sits on his haunches and resembles the Rodin's "The Thinker." Yank admiringly talks to the gorilla and complements his strong arms and chest. Yank sympathizes with the Gorilla who seems to want to challenge the "challenge de whole woild" by pounding his chest. Yank attempts to befriend the ape. He tells the ape that they are alike, as they are both caged and taunted. Yank believes he and the Ape belong to the same club and calls him brother. Yank releases the Gorilla from his cage and approaches the ape to shake his hand. The Gorilla springs on Yank, crushes Yank with his massive arms and then tosses Yank into his cage. Yank dies in the Gorilla's cage as a chorus of monkeys is heard from surrounding cages.
Scenes Seven and Eight complete Yank's deterioration into an animalistic state. While in Scene Seven Yank rejects the his "ape" identity, he embraces it again in Scene Eight as the animal world suddenly presents itself as his last hope of "belonging"." Yank cannot meld himself into any societal group and is finally destroyed by his attempts to befriend the animal group. Hubert Zapf, in O'Neill's Hairy Ape and the Reversal of Hegelian Dialectics characterizes Yank as the result of social progress, "Modern man's loss of any sort of cultural or social identity the anonymous, non-communicative nature of industrial society; the captivity of individuals in circumstances alien to their most fundamental anthropological needs."
Initially Yank sees himself as the motivator of progress—the steel and the engine that drives the Ocean Liner or modern society. Yank does not realize that as the "mover," the industrial worker, he is caged in the bottom of the ship and never feels any of the benefits of the ship's movement. While Yank shovels coal into the engine, the upper classes, symbolically on the top deck lounge on the promenade deck and take in the sea breeze. Technology has further separated and spread upper and lower classes.
Zapf compared this phenomenon to Hegelian Dialectics. Hegel, a famous philosopher, suggested that progress is a process where two antithetical forces resolve into a new synthesis where opposing forces are preserved. However, O'Neill presents many sets of antithetical forces, but reaches no synthesis. The play resolves with the death of the worker, the death of Yank. Death is the antithesis of progress.
Thus O'Neill deconstructs industrial progress as a means of human progress. O'Neill dramatizes the industrial worker forcefully deteriorated into a primitive, animal-like state by the upper, aristocratic class. The jobs created by steel companies treat men like work animals: they are caged, do one task, and have no need for intellectual thought. Where the poor have regressed to a more natural, animalistic state, the aristocracy has ascended so far above nature they have become artificial beings. Mildred expresses this in Scene Two. She, like Yank, seeks to find synthesis, a new "resolution" between the classes. The synthesis both seek is embodied in the theme of "belonging."
This sense of "not belonging" is the predicament of modern society. Cast into class identities from birth, one becomes the product of the culture and industry they were born into. Yank nor Mildred identify fully with their societal class because they didn't choose them. Mildred describes herself as the "waste" of her father's steel company—she benefits from the rewards, but has no idea of the work and vigor that brought them. Yank was born into a working class family from NY and had no opportunity for education or job other than his own. Neither Yank nor Mildred "belong" because they did not join.
The audience journeys with Yank in his fatal quest to find belonging. O'Neill exposes the impossibility of his task, the attempt to define and inscribe one's identity in a world where it has already been sealed.