Once, there were four worlds, nestled like pages in a book, each pulsing with fantastical power and connected by a single city: London. Until the magic grew too fast and forced the worlds to seal the doors between them in a desperate gamble to protect their own. The few magicians who could still open the doors grew more rare as time passed and now, only three Antari are known in recent memory—Kell Maresh of Red London, Delilah Bard of Grey London, and Holland Vosijk, of White London.

On a mountainside at the edge of the Kaigenese Empire live the most powerful warriors in the world, superhumans capable of raising the sea and wielding blades of ice. For hundreds of years, the fighters of the Kusanagi Peninsula have held the Empire's enemies at bay, earning their frozen spit of land the name "The Sword of Kaigen". Born into Kusanagi's legendary Matsuda family, f14-year-old Mamoru has always known his purpose: To master his family's fighting techniques and defend his homeland.

The Catenan Republic—the Hierarchy—may rule the world now, but they do not know everything. I tell them my name is Vis Telimus. I tell them I was orphaned after a tragic accident three years ago, and that good fortune alone has led to my acceptance into their most prestigious school. I tell them that once I graduate, I will gladly join the rest of civilized society in allowing my strength, my drive, and my focus—what they call Will—to be leeched away and added to the power of those above me, as millions already do. As all must eventually do.

In a corporate-dominated spacefaring future, planetary missions must be approved and supplied by the Company. Exploratory teams are accompanied by Company-supplied security androids, for their own safety. But in a society where contracts are awarded to the lowest bidder, safety isn’t a primary concern. On a distant planet, a team of scientists are conducting surface tests, shadowed by their Company-supplied ‘droid—a self-aware SecUnit that has hacked its own governor module, and refers to itself (though never out loud) as “Murderbot.”

Piranesi lives in the House. Perhaps he always has. In his notebooks, day after day, he makes a clear and careful record of its wonders: the labyrinth of halls, the thousands upon thousands of statues, the tides that thunder up staircases, the clouds that move in slow procession through the upper halls. On Tuesdays and Fridays Piranesi sees his friend, the Other. At other times he brings tributes of food to the Dead. But mostly, he is alone.