Also known as a death snail or a skull slug
A rather large armed group slowly walks the road. Unless you get to see what they transport, you could think it is a caravan with expensive goods, or the soldiers escort someone important. But this is a prisoner transport, on the way to mines, criminals on their way for punishment.
The soldiers may be willing to talk, the captain will have a few questions on you and the road, but they will keep distance, and part soon.