内容简介：
In the fourth book of the series, Amy uses the time machine to observe the most famous anti-war demonstration of the Vietnam War era. Her objective: uncover the mystery surrounding the controversial shooting of Kent State University students. But Amy miscalculates and finds herself staring down the rifle muzzles of the Ohio National Guard as they are about to fire Determined to find and rescue their friend, Andy and Mark embark on a journey in time that takes them through those fateful days of May, 1970. Along the way the boys experience the rage of student demonstrators, feel the frustration of the authorities, and sense the desperation of both sides as they speed toward a violent climax. With the city under curfew and the campus burning, can Andy and Mark complete their mission and prevent Amy from becoming another victim of the day the War came home? ""W. F. Reed, using the literary convention of time traveling, has creatively and accurately captured the emotion and passion I experienced on May 4, 1970 during the terrible killing and wounding of Kent State University students."" "-Jerry M. Lewis, Faculty Marshal, May 2-4, 1970."