In the tradition of her bestselling, award-winning phenomenon, The Giver, Lois Lowry delivers a story about censorship, comfort, complicity, and the radical power of books to open portals and unlock our humanity through our most powerful tool: the imagination.

Twins Tessa and Theo live in a world ruled by the tyrannical Koziris, where there are no dangers or rebels... or so they've been told. In this world, citizens live long lives, and while many hate Koziris, they are comfortable and safe. So, when Tessa's brother disappears, nobody wants to discuss it. But then Miriam, their 135-year-old neighbor, slips Tessa a key - not only to her brother's disappearance, but to the source of all real magic ... books.

As Tessa and her parents begin their search for Theo, Tessa learns that books not only tell us stories - they open portals and unlock our humanity through our most powerful tool: the imagination. Once that truth has been revealed, Tessa won't be able to rest until she has retrieved her twin and society itself has been transformed.

Two-time Newbery-winner Lois Lowry has crafted a narrative that feels at once prescient and eternal: in this world, the imagination isthe revolution. Not only does Building 903sit in the same resonant space as The Giver Quartet, but it is also a profound addition to Lois's enduring body of work - and a testament to the strength and value of her voice, vision, and legacy.