Captain Mark Isen, who slugged it out heroically with present- day Koreans in Ruggero's 38 North Yankee (1990), now travels to Mexico to advise that country's unenthusiastic troops in the drug war. In exchange for economic concessions and an easing of immigration regulations, the Mexican government has agreed to Operation Sentinel--a joint effort between the Mexican and US military to weaken and defeat the drug merchants who have been operating with impunity in northern Mexico. The operation is not going well. Bitterly and openly resented by the Mexican officers, minimally armed, and unsure of their authority, the American advisors make little headway until Mark Isen arrives. Relieving the demoralized advisor attached to a small army unit near Tampico, Isen finds scrubby, undisciplined, poorly supplied troops led by an intelligent but ineffectual officer. Isen tactfully applies his weak Spanish and his formidable soldiering skills and sets to work showing the prickly Captain Cortizo how to shape his men into a fighting unit. While Isen battles national pride, corrupt police, brutal heat, and hobbling regulations, Heinrich Wolf, a German in the pay of the still-dangerous Soviets, executes his elaborate plan to bring the tools of his terrorist trade through Mexico and into the US in order to bring that cocky nation to its knees--and Mark Isen's war on drugs becomes ten times trickier. All of this is bad news for Mrs. Isen, who would very much like her husband home and in a nice, safe instructor slot at West Point. As usual, Ruggero is all business. Mark Isen is a soldier's soldier and the story is a soldier's story--well told, but with no frills or comforts for the casual civilian.