The Time Traveller is an English scientist and gentleman inventor living in Richmond, Surrey, in Victorian England. As the narrator he recounts the Traveller's lecture to his weekly dinner guests that time is simply a fourth dimension and his demonstration of a tabletop model machine for travelling through it. He reveals that he has built a machine capable of carrying a person through time, and returns at dinner the following week to recount a remarkable tale, becoming the new narrator.

In the new narrative, the Time Traveller tests his device with a journey that takes him to A.D. 802,701, where he meets the Eloi, a society of small, elegant, childlike adults. They live in small communities within large and futuristic yet slowly deteriorating buildings, doing no work and having a frugivorous diet. His efforts to communicate with them are hampered by their lack of curiosity or discipline, and he speculates that they are a peaceful, communist society, the result of humanity conquering nature with technology, and subsequently evolving to adapt to an environment in which strength and intellect are no longer advantageous to survival.