The novel opens to the mysterious Le Cirque des Rêves, a circus that “arrives without warning” and is only open at night. This is the main setting of the novel, though the story jumps back and forth across the globe and throughout the nineteenth and twentieth centuries. After a short prologue describing the circus—“No color at all […] Black-and-white stripes on grey sky; countless tents of varying shapes and sizes, with an elaborate wrought-iron fence encasing them”—the story begins in New York City in 1873.
Prospero the Enchanter finishes his magic show to find a five-year-old girl waiting in his dressing room. Celia Bowen is his daughter, and her mother has committed suicide, leaving behind the child and a note. Prospero (whose real name is Hector Bowen) is uninterested in Celia until she begins to make teacups move with her mind, demonstrating innate magical abilities. He begins to train her as a magician and arranges a meeting with Mr. A.H., another magician and Hector’s lifelong rival. The two magicians have been competing against one another, using their apprentices as proxies, for centuries. Hector offers Celia as his new competitor, against anyone of Mr. A.H.’s choosing. They agree, and Mr. A.H. burns a ring into Celia’s finger to commit her to the competition.
While Hector trains Celia, Mr. A.H. finds his new apprentice in an orphanage and begins his magical lessons as well. He keeps the boy in isolation, taking him out to see magic shows as part of his education, and puts him up in his own apartment in London when he turns 19. On his own, the young man gives himself a name, Marco Alisdair, and quickly meets a young woman named Isobel Martin, a fortune-teller of mysterious origins, who moves in with him.
In the meantime, a theater producer named Chandresh Christophe Lefevre has invited a group of collaborators to his home for a Midnight Dinner, where he presents them with his new idea for a circus, “like no circus anyone has ever seen.” The group begins immediately, and soon they have found a contortionist named Tsukiko, and begin to audition illusionists; Marco, who has taken a job as Chandresh’s assistant, watches Celia Bowen’s audition and recognizes her as his opponent in the competition. He tells Isobel about this, and she offers to travel with the circus as well, to keep watch over Celia and her magic performances. She sends Marco letters as often as she can, but it is simply not enough information for Marco.
The opening night of the circus, the multi-colored bonfire is lit, and at that very same moment, one of the performers goes into labor, giving birth to twins who are known to the circus members as Widget and Poppet. They become an essential part of the circus, and each develops a particular magic skill: Widget is able to read people’s pasts, while Poppet has visions of the future. The circus itself is encased in magic, thanks to a spell that Marco has placed on it, anchored within the bonfire. Chandresh is not aware of the real magic that is going on in his venue, and Marco has to erase his memory on a regular basis to ensure he does not realize what is going on. The other organizers of the circus, including Ethan Barris, the engineer, and Tara and Lainie Burgess, begin to realize that they are not aging properly; Tara comes to speak with Ethan about her concerns, and he sends her to speak with “the man in the gray suit,” Mr. A.H., who knows much more than he reveals. Immediately following Tara’s conversation with the magician, however, she is overtaken by a strange impulse to throw herself in front of a moving train, committing suicide. Her sister Lainie comes to speak with Ethan about the tragedy, and he admits that he knows what is going on in Le Cirque des Rêves but cannot reveal anything, as he has promised to keep it a secret. In fact, Ethan knows all about the competition between Celia and Marco and has agreed to create a tent, known as the Labyrinth, where they can both perform in collaboration.
In Concord, Massachusetts, in 1902, a young man named Bailey Clarke attends Le Cirque des Rêves for the first time. A few years earlier, he snuck into the circus during the day on a dare, and was ushered out by one of the performers, who gave him her glove as proof that he had actually snuck in. During this visit, he visits Isobel, who informs him that he is “part of a chain of events,” though she does not specify what those events are; she also tells him that he is looking for Poppet. He stumbles upon Poppet, who happens to be the performer that gave him her glove years earlier. They become friends, and Bailey receives a free lifetime pass to the circus. Poppet has her own reasons for befriending Bailey: she has a vague vision of disaster, and in her vision it is Bailey who rescues the circus and all of its performers. She cannot say when this will happen, but she is sure that Bailey is part of the solution.
Le Cirque des Rêves is developing a strong following, thanks to the efforts of Herr Friedrick Thiessen, who made the clock that stands in the middle of the circus. After a meeting with Ethan Barris, Herr Thiessen creates a clock for him and doesn’t hear from him again. On vacation in France, a friend mentions the clock and invites him to the circus to see it. Thiessen is so impressed with Le Cirque des Rêves that he writes a newspaper column about it, which is then published throughout Europe. This brings together a group of circus fans, known as the revêurs, many of whom follow the circus around the world. They are known for dressing in black and white, with a single dash of red, such as a scarf or hat, and have a secret method of informing each other of the circus’s next location. Thiessen begins a correspondence with Celia Bowen, not realizing that she is the circus’s illusionist, and the two maintain a close friendship that lasts until Thiessen’s death.
The more that Celia and Marco get to know each other, the more attracted they are to one another. While Marco knew that Celia was his opponent from the moment he saw her perform, Celia was not aware of her opponent’s identity for years after joining Le Cirque des Rêves. Without knowing who he was, Celia still felt a deep connection to him, especially when she enters the Ice Garden, one of Marco’s creations; he feels the same connection when he enters the Wishing Tree that Celia created. Celia finally realizes that Marco is her competitor when she accidentally takes his umbrella from a café in London—as he runs after her to retrieve his umbrella, she realizes that he has placed a protective spell on it, keeping her much drier than an ordinary umbrella would.
The competitors steal quiet moments for conversation, much to the chagrin of their guardians, Hector and Mr. A.H., who often appear to interrupt them or warn each of them that they should be working against one another, not falling in love. By this time, Hector Bowen has become a ghost, officially dead but able to appear to people whenever he chooses; he keeps watch over Celia, berating her for collaborating and connecting romantically with the man who should be her rival. After one such conversation with Mr. A.H., Marco announces to his teacher, “I’m in love with her,” and walks into the ballroom where Celia is dancing with Herr Thiessen and kisses her. He then magically erases the memory of this moment from the minds of all in attendance, but it is a turning point for his relationship with Celia, as they both are aware of the depth of their feelings for one another. It is also an important moment because Isobel, who has been suspicious of their connection all along, overhears the conversation between Marco and Mr. A.H., and decides that she must leave the circus so as not to come between the two lovers. Before leaving, Isobel undoes a protective spell she had cast over the circus, which puts the circus members in peril. At that same moment, Chandresh, fueled by alcohol and a conversation he had with the ghost of Hector Bowen, is searching the circus grounds for Mr. A.H. in order to kill him. He throws a knife at the magician, who steps out of the way at the last minute, and the knife hits and kills Herr Thiessen, bringing a note of sadness over Le Cirque des Rêves.
Marco and Celia realize that there is no end point to their competition, and that it is only over once one of the competitors dies; distraught, they attempt to come up with ways to end the competition, to no avail, and each one offers to commit suicide to save the other. Marco discusses the competition with Tsukiko the contortionist, and learns that she, too, was once Mr. A.H.’s apprentice. Tsukiko won her competition because her opponent “set herself on fire. Ignited a pillar of flame and stepped into it as though it were water.” She encourages Marco to do the same, telling him that Celia is the greater loss to the circus. As Marco begins to sacrifice himself in the fire, Celia leaps into his arms and the two are magically transported through the bonfire and end up deep within the circus, neither dead nor alive. They remain together within the circus indefinitely, and the competition must be declared a stalemate.
Unfortunately, the central bonfire of Le Cirque des Rêves has gone out, and the circus cannot survive without it—Celia and Marco realize that they must find someone to relight the fire and take charge of the circus in order for it to continue. Recalling Poppet’s vision of destruction and salvation, they realize that Bailey Clarke is to be the circus’s caretaker. Celia explains to him that he must carry part of the circus within him, “tied very tightly to the circus itself.” Bailey agrees, and carefully follows her directions to re-light the fire.
The story jumps to Paris, in 1903, as Widget and Poppet have a conversation with Mr. A.H. to negotiate the official end of the competition between Celia and Marco, and to take control of Le Cirque des Rêves. Mr. A.H. agrees, selling Widget the circus for a story—the story of the circus itself. Widget begins his story with the first line of The Night Circus: “The circus arrives without warning.”
