Captain Mark Isen, hero of Ruggero's 38 North Yankee ( LJ 5/1/90), makes a second appearance, this time in a technothriller set in Mexico. Isen, assigned to a U.S. Army drug interdiction program, has to cope with Mexican opposition, incompetence, and apathy in his primary training and liaison role, as well as with a group of German terrorists armed with chemical weapons that is operating out of Mexico. A fast-paced piece of genre fiction, the book is somewhat weakened by Ruggero's treatment of his Mexican and terrorist characters, whose individuals remain little more than cardboard stereotypes for the Americans to encounter. This weakness is unlikely to influence readers looking for a military thriller, however, and the title will undoubtedly be in heavy demand, particularly with readers of Ruggero's first novel. Recommended for collections where the works of Tom Clancy and Larry Bond have been popular.-- Stanley Planton, Ohio Univ.-Chillicothe Lib.