Joe becomes conscious again, as if he is resurfacing after a stretch of drowning. Though he cannot see or hear, he soon realizes that he feels doctors working on him, and he is grateful for their help. He feels a pinching on his left arm and finally realizes that they have cut his arm off. Joe's immediate reaction is to feel angry and victimized: the doctors have cut the arm off because they are too lazy to fix it and Joe has no way of protesting. Joe wonders how they will dispose of the arm. Suddenly, Joe realizes with panic that the ring his girlfriend, Kareen, gave him is on the hand that is now gone.
Joe's memory of his last night with Kareen takes over. Kareen gives him the ring, which her mother gave her, for him to wear on his little finger. They kiss on Kareen's couch as she tells him her fears about him going to war. Kareen's father, Mike,—a coal miner whose body is bent from heavy labor—comes in and orders them to get up from the couch. In a moment of softness, Mike orders them both into Kareen's room to spend the night together before Joe leaves in the morning.
Kareen and Joe spend the night holding each other, and Mike brings them breakfast in the morning. Kareen and Mike take Joe to the train station, where all the soldiers are leaving. Joe's mother and sisters are there as well. Joe says goodbye to all of them as patriotic songs and speeches blare in the background. A mother appears looking for her son, who has agreed to join the army so he could be let out of jail.
As Joe replays the memory of holding Kareen in his arms, it suddenly dawns on him that both of his arms have been amputated. He mentally cries out.
Joe feels extremely hot and suddenly experiences a memory of working on the railroad one summer in the desert with a boy named Howie. Joe and Howie work for one day only, passing out several times due to heat and muscle pain while rest of the crew—primarily Mexican men— continue working. Joe and Howie had decided to leave Shale City and join the work gang because Diane and Onie, their respective girlfriends, had cheated on them with another young man named Glen Hogan.
That night, Howie receives a telegram from Onie, renouncing Glen Hogan and begging Howie to come back. Joe knows that Onie is only renouncing Hogan because Hogan has dumped her for Joe's girlfriend, Diane; nonetheless, Joe decides to endorse Howie's early return to Shale City. The boys leave on a gravel train that same night.
On the train, Joe thinks regretfully about punching his best friend, Bill Harper, when Bill told him about Diane and Glen getting together. Joe remembers all the history that he and Bill have together, having been best friends for years. Joe vows to make up with Bill when he gets back to Shale City.
Joe and Howie get into Shale City. Howie immediately heads toward Onie's house, leaving Joe to walk home by himself. Happily, Joe realizes that he has wandered onto Diane's street on his way home. Across the street from Diane's house, Joe sees Diane kiss a boy goodnight on her front steps. Joe realizes that the boy is Bill Harper. Joe walks home, feeling intense self-loathing and loneliness. He cries in bed, feeling that his life has changed.
Joe comes back out of the memory and realizes how long ago the events occurred—before he even moved to Los Angeles with his family. Joe has since received a letter saying that Bill Harper died in the war; Joe considers Bill doubly lucky for having gotten Diane and then having been killed. Joe finally feels that he is cooling off, though his mind is still muddled.
Memories continue to serve as Joe's escape from the pain and discomfort of his current position, although the memories seem to come upon him without his control rather than happen at his bidding. The boundary between his memory and his conscious, present state becomes increasingly blurred. Joe himself recognizes this blurring in Chapter iv, when it takes him a moment to realize that his sense of déjà vu is due to the fact that he is mentally reliving a scene from his past. In this fevered state, Joe worries about his sanity, about his consciousness being "all mixed up." This fight for sanity in the midst of his dips in and out of consciousness and of his overwhelming memories characterizes all of Book I.
Chapter iii offers several examples of the filmic techniques of Johnny Got His Gun. When Joe thinks about the ring on the hand of the arm that has just been amputated, the text immediately switches to a flashback dialogue scene between Joe and Kareen, when Kareen gave the ring to Joe. This quick, unannounced scene change is a technique that has its origins in the visual medium of film: the link between the two scenes is the a visual one—the mental image of the ring. Similarly, the scene of Joe's goodbye to Kareen and his family at the train station is interspersed with snatches of patriotic speech and song, in the way a film would use the technique of montage.
Chapter iii introduces several characters who are in undesirable positions and who seem to have no choice or agency in the matter. First, Kareen's father, Mike, has worked in the mines for twenty-eight years, suffering bodily damage, and then has worked for the railroad. Trumbo portrays Mike as despising both jobs but having to work them anyway. Mike, in turn, highlights Joe's lack of choice in serving in the army, urging Joe to be on time for the Army train lest the Americans shoot him before the Germans. Furthermore, a woman arrives at the train station looking for her son, who has apparently been given the option of either remaining in jail or going to war, and has chosen to go. (This woman, along with the story about her son, reappears later in Chapter xvi.) In each of these situations, freedom of choice disappears, as the options one is offered are equally undesirable—working at hard labor or living in poverty; getting killed in the war or getting shot for desertion; remaining in jail or going to war. We come to see how democratic situations, though they extol an individual's control over his own destiny, can become a screen for an environment of unequal exploitation.
Chapter iv consists of one long memory of the scenario in which Joe loses his best friend and his girlfriend all at once in high school. The scenario is connected in Joe's mind with the severe bodily pain that he experiences by working one day on a railroad section gang in the desert at that same time. This remembered bodily pain is, of course, connected to Joe's current bodily pain as he emerges from his operation in a fevered state. The connection between Joe's loss of friends and his physical and emotional pain highlights the individual isolation of pain, which is felt inside oneself and cannot be communicated to others.