All right, let's recap. The play ends with Nell dead in her trash bin, Nagg trapped in his trash bin with the alarm clock sitting on top of it, Clov in the doorway dressed to make an exit, and Hamm pushing his way through his final soliloquy before covering his face with his handkerchief.
A warning: the play is very funny, but the end is, without a doubt, somber. So just know that there's a lot of depressing discussion ahead.
First, let's consider Hamm's soliloquy. Point one: Hamm is blind and wheelchair-bound. This means that, if Clov were to leave him and Nagg were to cease responding to him, he really would be totally alone in the dark, waiting to starve to death. The physical world would barely exist for him. This is a nightmare that Hamm conjures up from time to time during the play, and it is clearly one of his greatest fears. We might think that Hamm would be getting his just desserts – he is a tyrant after all – but the situation is so awful that we wouldn't wish it on anyone.
Point two: remember how we said Hamm's a tyrant? Well, we meant it. He is so self-centered that it borders on solipsism. Solipsism is the philosophical idea that nothing in the world exists outside of your own mind – which may sound kind of crazy, but is really, really hard to disprove. Hamm has been playing God throughout the play, and here he is unmaking his world – taking it apart piece by piece. It's the opposite of the creation story.
There is one key line we'll focus on in Hamm's soliloquy: "Old endgame, lost of old, play and lose and have done with losing" (1.799). This line recalls the title of the play, which we discuss in "What's With the Title?" – and that key point in a game of chess when the game has been lost and the loser just has to sit and let the match play itself out.
Trapped in their bunker in Endgame's post-apocalyptic world, Hamm and Clov frequently curse their situation and talk about how miserable life is, but there is something that keeps them clinging to it. The world Beckett has imagined is so awful that love of life just amounts to self-torture.
Which brings us to Clov. Throughout the play, Clov has threatened to leave Hamm. Clov's departure now seems imminent: he is dressed with his Panama hat, his umbrella, and his bag. Still, Hamm and Clov have made a plan that, if Clov were ever to leave, he would set the alarm clock to go off as a signal of his departure – and the alarm clock, sitting on Nagg's trash bin, has not been set. Even though Clov has dressed to go, it seems very likely that he will not be able to bring himself to do it.
The thing is, this scene quite possibly has happened many times before, and perhaps will happen many times again. The inconclusiveness may be even worse than if we knew for certain that Clov has left Hamm alone to die. The two choose to prolong their torment day after day.