Scarlett Dragna has never left the small island where she lives with her sister Tella and their powerful and cruel father. Now, Scarlett's father has arranged a marriage for her, and Scarlett thinks her dreams of seeing Caraval – the faraway, once-a-year performance where the audience participates in the events – are over.

But this year, the long-awaited invitation finally arrives for Scarlett. With the help of a mysterious sailor, Tella kidnaps Scarlett to the show. However, as soon as they arrive, Tella is abducted by the brilliant organizer of Caraval, Legend. It turns out that this season's Caraval revolves around Tella, and whoever finds her first is the winner.

Scarlett has been told that everything that happens during Caraval is just an elaborate performance. Nevertheless, she becomes entangled in a game of love, heartbreak, and magic. And whether Caraval is real or not, Scarlett must find Tella before the five nights of the game are over, or a dangerous chain reaction of consequences will be triggered, and her beloved sister will disappear forever.