Not since Joseph Wambaugh's best-selling "The Onion Field" has there been a true police story as fascinating, as totally gripping as . . . "Lines And Shadows." The media hailed them as heroes. Others denounced them as lawless renegades. A squad of tough cops called the Border Crime Task Force. A commando team sent to patrol the snake-infested no-man's-land south of San Diego. Not to apprehend the thousands of illegal aliens slipping into the U.S., but to stop the ruthless bandits who preyed on them nightly--relentlessly robbing, raping and murdering defenseless men, women and children. The task force plan was simple. They would disguise themselves as illegal aliens. They would confront the murderous shadows of the night. Yet each time they walked into the violent blackness along the border, they came closer to another boundary line--a fragile line within each man. and crossing it meant destroying their sanity and their lives.