The tunnel was a blinding chaos of tactical light and suffocating, sulfurous smoke. We were deep inside the conduit now, running a gauntlet of desperate, terrified men who had realized too late that their employer had abandoned them. The fight was brutal, confined, and utterly devoid of mercy.

I moved at the front, my movements less those of a man and more those of an automated, perfectly calibrated weapon. The coordinates of the villa’s primary infirmary—the junction where Isabella was ...