The narrator has been told a story by a friend from the Socialist League in Victorian England, which he informs the reader he will tell from the first-person perspective. The character, who tells others to call him "William Guest" later in the story, goes to sleep in late-19th-century England and wakes up in the same spot in the 21st century. He is taken under the wing of Dick Hammond, who shows him life in the 21st century by inviting him to travel up the Thames to help with the harvest. On the way, William is able to learn about the history of England between the 19th and 21st centuries, especially from Dick's great-great-grandfather Old Hammond, and about the current society in England which differs from the England of the 19th century in many ways, including the systems of education, justice, and marriage. They also pick up and drop off a number of characters along the way, the most prominent of whom are Dick's past lover Clara and William's love interest Ellen. Dick, William, Clara, and Ellen reach the site where Dick has friends harvesting after a number of days of travel and after William has revealed where and when he is truly from to Ellen. At a festive dinner, the other characters suddenly stop being able to see William, and he walks away into a black fog. He wakes up back in the 19th century, but says that what he saw was more a vision than a dream.