"Used to be that way on my world, too," Cassie says. "Took a couple centuries after guns were invented until lancers on horseback became obsolete. But as soon as one person could fire hundreds of bullets a minute, that was pretty much it for swords on the battlefield.

"Unless you're dealing with eight-foot centaurs from another dimension who can take a LOT of bullets. But most humans didn't know about those until a couple decades ago."