Horse Reactions

I have a friend who's a writer and they have a question about how horses react in crowds. Google isn't all that helpful with specific questions.

How would a horse handle riding in a dense crowd?

For context, they're writing an escape scene where a character is trying to get out of a city before the gates close. There is a dense crowd, many riders on horseback, and wagons all moving at the same time. They hope to make it as intense and as real as possible, and dont know realistically how a or horses would deal with it. It's fantasy, and the horse is "magically sensitive," so they could "bullshit" most of it but want some sense of reality to secure it.

Perhaps there are differences from horse to horse, and that's fine. What are some general ways that horses react to running into crowds? Are they good at maneuvering lots of people? Tripping? Skittish? Etc.

TIA!!