'Horse thunder' is what I call the sound of galloping hooves.

A Sound of Thunder.

A Sound of Thunder,

With the Mongolian horse warfare, I did a lot of research into the Mongol art of war.

I started looking into horse history books and came across the actual story of this half-breed endurance horseman and his painted mustang Hidalgo. I wasn't really sure if I was going to do the movie at that point.

I go where the sound of thunder is.