I was walking down the street when I saw someone who I vaguely recognized. I stopped and turned to get a better look, but they were already gone. I shrugged it off and continued on my way.

A few minutes later, I was stopped at a red light when I saw the same person again. They were standing on the corner, staring at me in shock. I couldn't believe it. I had never seen this person before in my life.

I got out of my car and walked over to them. "Do I know you?" I asked.

They shook their head. "No," they said. "But you look just like someone I know."

"Who?" I asked.

"Me," they said. "From the future."

I stared at them in disbelief. "What are you talking about?" I asked.

"I'm from the future," they repeated. "I came back to warn you."

"Warn me about what?" I asked.

"About the war," they said. "The war that's coming."

"What war?" I asked.

"The war between humans and machines," they said. "It's going to happen in a few years, and it's going to destroy the world."

I didn't know what to say. I couldn't believe what I was hearing.

"You have to stop it," they said. "You're the only one who can."

"How?" I asked.

"I don't know," they said. "But you have to find a way."

And then they were gone.

I stood there for a long time, trying to process what had just happened. I didn't know if I believed them, but I couldn't take the chance. I had to do something.

I got back in my car and drove home. I spent the rest of the day trying to figure out what I could do to stop the war. I read everything I could find about artificial intelligence and robotics. I talked to experts in the field. I even started working on my own project, a way to create a fail-safe for artificial intelligence.

I don't know if I'll be able to stop the war, but I'm going to try. I have to try.