Julien de Montfort has spent years calling himself a playwright without ever finishing a play. Then a ticket to the Théâtre de l’Impossible leads him into a performance unlike anything he has seen: forests deeper than the stage can hold, music that seems to reach inside its listeners, and actors whose faces appear in portraits painted centuries apart.

Determined to discover how the illusion is created, Julien talks his way through the backstage door and into an unpaid apprenticeship with the theater’s secretive company. But the longer he remains, the harder it becomes to dismiss what he sees. The theater keeps its own hours. Its doors open only when they choose. And Madeleine Aubry, its watchful young stage manager, never steps outside.

As Julien is drawn closer to Madeleine and the strange family surrounding her, he begins to suspect that the theater did not admit him by accident. Something within its walls has been waiting for him—and the unfinished story it wants him to complete may be older than his own name.