"Nights at the Circus" is a fantastical tale set in the late 19th century, centering around a trapeze artist who claims to be a swan princess with wings. A journalist is intrigued by her story and joins the circus to uncover the truth. As the troupe travels from London to Siberia, the journalist becomes increasingly enchanted by the strange world of circus performers and his relationship with the trapeze artist deepens. The book explores themes of love, freedom, and the blurred lines between reality and illusion.

The novel follows the adventures of an eccentric, violent, and mentally unstable protagonist who is released from an asylum by his psychiatrist. The pair embark on a chaotic journey across Europe and America, encountering a variety of strange and often dangerous situations. The narrative explores themes of insanity, violence, and the human condition, offering a dark and surreal critique of modern society.