Watch The Letters That Guided Us Full Movie Free Online 123Movies. The Letters That Guided Us opens in the wake of the US involvement in the Vietnam War. William Warren has just returned home from his tour and is seeing home and the people he left behind for the first time in years. Through the course of the 30-minute film, the audience hops into an adventure meeting allies, enemies, and people in between as they track three distinct storylines of William's life.