The Night Circus is a YA fantasy novel by Erin Morgenstern. The story revolves around a mysterious circus that arrives without warning and the fierce competition between two young illusionists, Celia and Marco. As the circus travels around the world, the feats of magic gain fantastical new heights with every stop. The lives of all those involved are swept up in a wake of spells and charms. But when Celia discovers that Marco is her adversary, they begin to think of the game not as a competition but as a wonderful collaboration. With no knowledge of how the game must end, they innocently tumble headfirst into love. Their masters still pull the strings, however, and this unforeseen occurrence forces them to intervene with dangerous consequences, leaving the lives of everyone from the performers to the patrons hanging in the balance.