The Time Traveller concludes that in order to recover his machine he must enter into the world of the Morlocks. In the distance, he sees what he describes as the Palace of Green Porcelain. Instead of visiting it, he decides that he must descend into one of the wells. When Weena sees him descend, she is very worried. He clambers down one of the wells for a long time, finally finding a small alcove where he can rest. He awakes to the touch of clammy fingers. Lighting a match, he sees several Morlocks running into the distance. He explores further and finds a vast chamber filled with Morlocks and the throbbing machines that pump air through the caves. The Morlocks are eating some kind of meat. Suddenly, the matches that he is using to ward off the Morlocks run out, and they seize him. He narrowly escapes back up the well.
Horribly frightened, he decides that he must find some way to defend himself from the Morlocks. He has to revise his theories. Over the next few days, he realizes that the meat the Morlocks were eating was probably Eloi, hunted at night. He now thinks that he understands why the Eloi dread the night. They speak of imminent "Dark Nights," and he realizes that the moon is waning. He imagines that his theory about the division of labour being carried to the extreme was right, that at one point the ancestors of the Morlocks must have been driven underground to work for the ancestors of the Eloi, but that now the balance of power has shifted. In their restful ease, the Eloi have grown weak, while the Morlocks have grown strong. He imagines that both are the descendents of man, and that the instinct against cannibalism must have gone out of style. He also imagines that his journey into the underworld must have horribly upset the Morlocks. Nervous, the traveller hastens to find a safe place to spend the night.
He decides to try to find safety in the Palace of Green Porcelain. With Weena on his shoulders, he begins to journey toward it. Weena walks alongside him for a while, stuffing his pockets with flowers, two of which he produces for his guests. He resumes his story. The journey takes longer than he thought, and as night falls they find themselves on the border of a great forest. The Time Traveller is out of matches, and is afraid to enter the woods with Morlocks about. He sets Weena down on top of a hill, and lets her sleep while he keeps watch. The night passes without harm.
The Time Traveller makes a journey into the underworld. This is a common element in fiction, especially in myths. In many ways, Wells's tale is like a myth, in that it is a story of a completely different world full of symbolic meaning.
The Time Traveller formulates a third theory on the world of the Eloi. Not only has capitalism led to a ghastly division of labour in which the workers must live underground, but the workers are now exacting revenge on their former masters. The Morlocks eat, hunt, and terrorize the Eloi, just as the ancestors of the Eloi metaphorically preyed on their subjugated workers.
This theory seems to represent some of Wells's own anxieties. Capitalist societies often produce tales about fears of an uprising from below. In Wells's tale, the uprising is an unavoidable evolutionary consequence. It should be noted that while Wells seems to attack communism earlier in the book, the Time Traveller's third and ultimate theory still incorporates the idea of class warfare, a way of looking at society that is a key element of Marxism.
I think it's important to realize that when the time traveller leaves in the end, he has with him a bag and a camera, so the reader can infer that he will return with proof.