Free man of color Benjamin January travels to Washington, DC, to track down a missing mathematician in this "excellent" pre–Civil War mystery ( Publishers Weekly, starred review).

New Orleans, 1838. Living in antebellum New Orleans as a free man of color, Benjamin January has always taken whatever work he could find. But when he suddenly loses his job playing piano at extravagant parties, he finds himself taking on an entirely new—and exceedingly dangerous—enterprise. Sugar planter Henri Viellard has hired Benjamin to travel with him to Washington, DC. Henri's friend, an elderly English mathematician named Selwyn Singletary, was last seen in Washington before he went missing. With Benjamin's help, Henri intends to track him down.

Plunged into a murky world of spies, slave snatchers, and dirty politicians, Benjamin uncovers a coded secret that he attempts to decipher with the help of a young Edgar Allan Poe. But a powerful ring of conspirators doesn't want the secret known. And they're ready to kill anyone who gets in their way.