Before dawn, Buford rides down the line and goes into the cupola of the Lutheran Seminary. He surveys the battle from there, hearing the first shots and seeing how the Confederates realize that they're facing more serious resistance then they expected.
Buford climbs down from the cupola and sends a letter to Reynolds, telling him they've begun the battle.
Buford observes the sights and sounds of the fight; he hears the "Rebel Yell" as the Confederates attack.
Buford goes to see Gamble, who tells him they've taken some prisoners. He realizes they're fighting Harry Heth's troops.
Buford and Gamble estimate that the whole Rebel Army will arrive by afternoon. Buford tells Gamble to keep holding off the early arrivals and orders Devin to add his troops to Gamble's line to help.
Buford sends a lieutenant off to the north with some troops, telling them to alert him if any Rebels start to arrive from that direction: he doesn't want to get flanked. A shell explodes near him at one point.
From the seminary, Buford sees the Confederate attack increase, with added artillery. Gamble suffers a concussion but gets back in the game shortly.
Buford doesn't think they can hold out much longer, as the artillery gets worse. He's worried that Reynolds won't show up…
Finally, Reynolds arrives, though his troops are further back. Buford explains the position to him, and Reynolds compliments him on a job well done. The Rebs will think they're just attacking Buford but will find themselves running right into Reynolds's fresh infantry.
Reynolds lets Buford withdraw his troops, as Reynolds's men pull into view.
Reynolds sends messages to Meade and the other commanders, explaining that they desperately need to get to high ground before the Confederates can. He thanks Buford again and rides off.
The Union Army—including the Iron Brigade (also known as the Black Hats), the best troops from the North, according to many—start to arrive and take up positions.
Reynolds returns and sends a lieutenant into town to tell the people to stay indoors. He compliments Buford again on his good tactics, and Buford feels great.
Buford and Reynolds ride out together as the Rebel cannons fire and more and more Union soldiers arrive to hold the field.
While riding, Reynolds gets shot and killed. Buford orders the body covered and taken away. Nearby, a woman catches her child, who had been playing on the road, and gets him away from the battleground.
Despite losing their commander, Reynolds's troops keep holding the line. Buford gradually withdraws his cavalry and takes them north, where more Confederates will be arriving.