Paris runs on light and noise, and Cole Whitaker makes both.

A burned-out American dropout turned rising star, he plays the clubs under the name VESPER and composes with the help of MUSES, a superintelligent AI that finishes his hooks before he can think them. Then, one night in the small hours, the machine tells him something no machine should know: that Napoleon Bonaparte begged with his dying breath to be buried on the banks of the Seine, that he lies instead in the wrong grave a mile from the water, and that the Emperor will never rest until someone carries him home to the river.

Is the AI reaching across the veil to the dead? Or is it a brilliant, unraveling machine building a lonely young man the most beautiful delusion of his life? Cole cannot tell. Neither can Camille, the Louvre conservator he loves, who trusts nothing she cannot prove, nor her father, a retired scholar who has spent a lifetime on the frontier between science and the séance.

To find the answer, they are drawn into the secret Paris the tourists never see, the closed galleries of the Louvre, the empire rooms of Versailles, the risen stone of a restored Notre-Dame, the endless bone tunnels of the catacombs, and toward the most audacious act the city has ever nearly witnessed.

Part supernatural thriller, part heist, part love story, part meditation on what our newest machines might let us hear in the oldest silence, Napoleon's Ghost asks whether the dead are ever truly gone, and whether it matters, when belief may be the only bridge across.