Why did Henry run back in the directions of the battle that he had just ran away from?

Henry ran back towards the battle out of a mix of guilt and a desire to prove his courage. After fleeing, he was overwhelmed by feelings of shame for abandoning his comrades and felt a strong urge to redeem himself. Additionally, witnessing the chaos and suffering of war ignited a sense of responsibility to support his fellow soldiers, prompting his return despite the danger.