Charlie can feel the deterioration accelerating. He thinks about suicide as a means to avoid the inevitable, but he cannot take the shadow Charlie’s life from him. He feels that he has simply borrowed his life and now must return it. He is becoming irritable and aggressive. He plays the stereo turned up loudly all through the night, not wanting to go to sleep and waste whatever time he has left. Eventually the landlord reports him to the police. He shatters the records and leaves them lying on the floor.

At his last therapy session with Dr. Strauss, Charlie has a strange episode in which he imagines that he is trying to get into a cave full of light but keeps banging into the entrance. He is afraid of the nothingness that he knows will come. He tells Dr. Strauss that he will not be back for more therapy sessions. There is no point since they both know what is going to happen.

At the lab, Charlie is finding it more difficult to type his reports. He is becoming more uncoordinated. He cannot do the mazes as fast, so he tells Burt he does not want to do them any longer. When Charlie tries to do the Rorschach Test, he finds that he cannot even remember what he was supposed to see. As with the therapy sessions, Charlie tells Burt that he will not be back for further tests.

Algernon has died, and Charlie keeps putting flowers on his grave in the backyard. He tries to read Milton, but he cannot remember all the words. He flashes back to his mother trying to teach him to read. He desperately wants to retain at least some of what he has learned.

One night as he walks the streets he forgets how to get back home. A policeman escorts him back, and when he wakes up he finds Alice there. She says she wants to make the most of the time they have left. Charlie manages to push away the shadow Charlie and make love to Alice, which he finds is so much different than sex with Fay. Eventually, Charlie becomes lethargic and tells Alice to leave. His motor skills are deteriorating along with his cognitive abilities. His landlady makes sure he has food, paid for by Dr. Strauss and the others.

Charlie intends to go to the Warren state home while he is still able to function independently. However, he goes back to the bakery and asks Mr. Donner for his old job back. A new worker, Klaus, makes fun of him, twisting his arm and not letting him go to the bathroom. When Charlie messes himself, Klaus releases him. The other workers berate Klaus, telling him to leave Charlie alone. As much as they laughed at Charlie before his operation, now they are very protective of him.

Charlie shows up at Miss Kinnian’s class, forgetting that he did not go there anymore. Miss Kinnian cries and runs out of the room. He decides it is time to go to the Warren home. He leaves a note for Miss Kinnian, Dr. Strauss, and Professor Nemur. He feels proud that he was the first “dumb person” to discover something important for science. His last request is that someone should put flowers on Algernon’s grave.