The guards were unhappy, grumbling to each other when out of the caravan master's earshot, and glaring at him when he wasn't looking. They would soon be passing through the land of an infamous robber baron, and allowing a sad old man on a sad old mule to join them would slow them down.
They glared at the old man whether he was looking or not, finding reasons to dislike him. His face was dour, and he brought down the mood of the whole caravan. His tunic bore a sigil like that of a knightly order, but not any order they had ever heard of, so he was surely some sort of charlatan. He had around his belt a strange old horn with strange old carvings; a pagan artifact, perhaps, sure to bring them bad luck.
The caravan master had said that the old man reminded him of his own grandfather, and that it would be a good deed to let him travel with them, even if inconvenient, and that was that. The guards would have to satisfy themselves with grumbling.
Although unfair, the fears of the guard were not unfounded. They were unable to make it through the robber baron's land during daylight, and as the sun set, they were attacked. A volley of arrows flew out from the brush on both sides of the road, landing in a circle around the caravan. They all got the message.
The sad old man hardly seemed to notice the arrows, but as the baron's men emerged and surrounded the wagons, he frowned. He let out a deep sigh, and lifted the strange old horn to his lips. The sound boomed like the echo of thunder, and reverberated as if in a great hall. Both guards and bandits started at movement on the edges of their vision; movement that soon resolved itself into ghostly figures.
Each figure was armored, although the only uniform feature was that the armor was battered and nicked. They held weapons of a style that no men now bore, but that farmers sometimes dug up from their fields. Their shields and banners bore the sigil like that of a knightly order, not one that any of the guards had heard of, but that matched the one on the tunic of the sad old man.
They fought like great knights, swinging their translucent weapons through bandits and felling them in single blows, although no wounds appeared. The sad old man watched watched the knights, no longer dour, with light in his eyes. When the last bandit fell, the knights turned to the old man and saluted him, then faded and disappeared.
The guards now regarded the old man cautiously, and were startled when he spoke. He asked about the lord of these lands, and how he could allow such bandits on an important road. They explained that the bandits worked for the lord, and sadness slowly settled on the old man once more.
The caravan master took charge of his caravan once again, ordering that they should get as far from this battlefield as they can before the sun fully set. As they got underway, one guard noticed the old man had left the group, and was moving slowly, but with determination, towards the castle of the robber baron.