Based on David Maraniss's book 'They Marched into Sunlight', a documentary telling the story of two seemingly unconnected events in October 1967 that changed the course of the Vietnam War. Whilst a US battalion unwittingly marched into a Viet Cong ambush which killed 61 young men, half a world away angry students at the University of Wisconsin were protesting the presence of Dow Chemical recruiters on campus.