After the battle Pierre makes his way down from the battery, past the medic station. He is just trying to get as far away from the whole horrible place as quickly as possible. The whole thing is just too much for him and he needs some time to process and digest.
He walks along the road, then lies down. For hours.
Finally, some passing soldiers set up camp near him. He wakes up and chums it up with them by pretending to be a much lower-ranking person than he really is. They give him some grub, and it’s the best thing he’s ever eaten.
He walks to town with these guys until they run into his horse groom.
There’s nowhere at the inn for Pierre to sleep, so he just bunks down in his carriage.