I hated this simulation. It felt ten kinds of wrong to allow something horrendous like an assassination of arguably one of our greatest presidents, but it was all part of the job. It was why this particular simulation was so important to our training. We had to learn that what we thought about right and wrong didn’t matter. At least not when it came to changing history. As a Glitcher, it was my job to make sure things stayed exactly the way the history books described without interference from a Butterfly.

The term Butterfly had thrown me for a loop when I’d first heard it. It seemed too, I don’t know, fluffy to describe a time-traveling criminal the same way you describe a really pretty bug. I mean, a time-traveling criminal is usually someone attempting to manipulate history with the full intention of screwing up the future, and there was nothing fluffy about that. But I learned quickly that the term Butterfly did not come from the beautiful insects I saw landing on the flowers outside my window. Instead, it referred to the butterfly effect.

In 1963, this guy named Edward Lorenz presented a theory to the New York Academy of Sciences that “a butterfly could flap its wings and set molecules of air in motion, which would move other molecules of air, in turn moving more molecules of air—eventually capable of starting a hurricane on the other side of the planet.” And everyone thought he was crazy for thinking something as small as a butterfly could start a snowball effect capable of wiping out whole cities.

He was laughed at.

He was called a fool.

And then thirty years later, they realized he was right.

So we called time-traveling criminals Butterflies, despite the fluffiness of the word, because they traveled back to the past to change something. They were the people who believed Hitler should have won World War II, that slavery should never have been abolished, or that women shouldn’t have been given the right to vote. That’s where Glitchers come in.

I glanced down at my watch. It was the exact same one the woman three rows up and two over was wearing. Everything from my light blue dress with the ten crinolines underneath to the way my hair was curled and pinned up to the back of my head like a poodle was historically accurate, down to the last piece of lace trim. Of course, I wasn’t exactly historically accurate, since unchaperoned twelve-year-olds weren’t a common sight at Ford’s Theatre, but that didn’t matter for a simulation. If I ever actually did this Glitch for real, I’d be an adult with years of time traveling under my belt. I swallowed hard and ignored the fact that the thought made my stomach feel like I’d swallowed a bucket of live snakes.