Of course, not all nags pulling the caravan were of the Sage Horse Species, but rather, it was the coachmen driving them who were in a state of invisibility— that's right, each wagon squadron was equipped with a Pikespirit, they served as coachmen, veterinarians, and were excellent Magic Assistants as well; their Entangle Spell proved to be incredibly useful in defensive battles.
However, for them, the spectacle of tens of thousands of people moving en masse was too magnificent and exciting. While curious, they were instinctively shy, preferring to hide and observe, which was their favorite thing to do.
Therefore, it led to the bizarre sight of the wagons moving according to plan without any visible drivers.
After all one hundred carriages had entered the new road, following a series of commands, another lengthy procession slowly made its way out.
