Revolution is a young adult novel by writer Jennifer Donnelly. In this novel, Andi is a teenager who has suffered one of the worst tragedies imaginable - the death of her younger brother. Andi struggles with this death, unable to put it behind her. In an attempt to force Andi to focus on her school work, her estranged father takes her to Paris where she finds the diary of a young actress who cared for the dauphin, Louis-Charles, during the French Revolution. Andi discovers she has a great deal in common with this young actress and a trip into the catacombs seems to pull them together, forcing Andi to learn a lesson from the deaths of two young, innocent boys. Revolution is a story of loss, but it is also a story of hope as the reader travels along with Andi to discover how just knowing her brother changed her entire perspective on life.

Andi is struggling at school because she rarely shows up, only appearing for music classes with her beloved teacher Nathan. The headmistress at her private school calls her into her office to discuss the senior thesis, a paper that will be a large portion of Andi's grade and be a deciding factor in whether she graduates with her class in the spring or not. Andi is unconcerned about this paper. In fact, Andi does not care if she graduates because she does not care if she lives. Andi's ten year old brother died two years ago, a tragedy that was followed by her parents' divorce and her mother's decent into depression.

Andi goes to a party at a schoolmate's house and nearly jumps off the roof in an attempted suicide, but is stopped by her schoolmate, Nick. Unfortunately the two are caught in an embrace by Nick's girlfriend, creating a social firestorm for Andi. Therefore when Andi's father insists on taking her to Paris so that Andi can work on her outline for the senior thesis, she reluctantly agrees to go. Andi once loved Paris, the city where her mother grew up, but continues to find it impossible to find happiness in anything.

Andi makes a deal with her father that if she finishes her thesis outline by the weekend that he will allow her to fly back to New York alone. Andi is anxious to return to the city out of concern for her mother whom her father had committed to a psychiatric facility. To begin her essay, Andi begins to read every book she can find on the composer Amade Malherbeau. Andi's topic is the influence of Malherbeau's music on modern guitarists. At the same time, Andi is trying to fix the latch on a Revolutionary era guitar case her father's friend has collected for a future museum for the Revolution. As Andi works the lock, she discovers a hidden compartment in which is hidden a diary written by a young actress who lived through the Revolution.

Andi reads the diary and discovers that the young actress, Alexandrine, was a servant to Louis-Charles, the son of Louis XVI. Andi's father is in Paris in order to do DNA testing on a heart thought to belong to Louis-Charles, taken from his chest upon his death in the Temple where he was kept prisoner by Robespierre throughout the final years of the Revolution. As Andi reads the diary and learns more about Alex and Louis-Charles, she begins to hope that the heart does not belong to the young dauphin.

As Andi learns more about Alex and the Revolution, she also develops a relationship with a young French man named Virgil. Despite this new hope in her life, Andi continues to grow depressed, especially when she learns the heart did in fact belong to Louis-Charles. Andi attempts to jump off the Eiffel Tower, but is stopped by Virgil. Virgil then takes Andi into the catacombs where Alex lived out her final moments after being shot by a guard. During a party in which Andi and Virgil play as part of a band, a police raid causes them to become separated. Andi falls as she runs from the police and hits her head. Suddenly Andi wakes during the final days of Louis-Charles life. Andi takes over what Alex has started, shooting off fireworks to let the dauphin know he is not alone. On the last night, Andi is shot just as Alex was and finds herself hiding in the catacombs. She wakes up the next day back in the modern world with a new understanding of life.