Aztechs

In Aztechs, Shepard returns to the near-future setting of his Nebula Award-winning story, "R&R" (later part of Life During Wartime). El Rayo, the bustling border community grown up along the electrified fence along the U. S./Mexican border, is home to Eddie Poe, who earns his living by providing security. The men he hires are AWOL U. S. soldiers. AZTECH, a mysterious high-tech firm rumored to be run by a renegade U.
S. military AI named Montezuma, hires Eddie and his bodyguards to join AZTECH representative Montezuma 2 ("Z2") for a meeting with the Carbonell cartel. When the meeting goes sour and Z2 is badly wounded, one of the soldiers lobs a pocket nuke to cover their escape, and Eddie realizes he's no longer in control...