Towards the end of the play, Clov seems resolved to leave...
Hamm, but he's not entirely certain about it:
CLOV. I say to myself—sometimes, Clov, you must learn to suffer better than that if you want them to weary of punishing you—one day. I say to myself—sometimes, Clov, you must be better than that if you want them to let you go—one day. But I feel too old, and too far, to form new habits. Good, it'll never end, I'll never go.
Then one day, suddenly, it ends, it changes, I don't understand, it dies, or it's me, I don't understand that either. I ask the words that remain—sleeping, waking, morning, evening. They have nothing to say.
I open the door of the cell and go. I am so bowed I only see my feet, if I open my eyes, and between my legs a little trail of black dust. I say to myself that the earth is extinguished, though I never saw it lit.
On the one hand, Clov wants to leave. He has good reason to leave, having endured Hamm's mistreatment for all of his life, but he's not sure if that's a good enough reason to leave him.
On the other hand, Clov has reasons for not leaving. He's too old, he says. He doesn't want change, and he's also afraid that his life will be meaningless without Hamm.
Clov has an innate sense of obligation to Hamm. Clov knows that Hamm can's survive without him. Both Clov and Hamm are afraid to be alone, even though they insist otherwise, and they're particularly afraid of being without each other.
At the end of the play, Clov is positioned at the door. He's "dressed for the road" in his Panama hat and tweed coat, his raincoat over his arm, his umbrella and bag in hand, It appears that he intends to leave.
Hamm gives a lengthy stream-of-consciousness monologue which leads to the last line of the play:
The play ends in tableau, with Hamm sitting motionless in his chair with a handkerchief over his face, and Clov standing at the door, "impassive and motionless, his eyes fixed on Hamm."
Is Hamm's last line a statement, a command, or a request? Does Clov stay, or does he go? These are open questions to which Beckett gives no answers.