Jimmy and I stood there, staring blankly at the remains of the time machine. All I could think of was home, my sweet twenty-sixth century home. Now I would never get back. I would never see my family again, or any of my friends. Well, except for Jimmy, and his friend status was a bit questionable, seeing as how this was entirely his fault. I turned to him, slowly counting to 10 under my breath.
"Jimmy," I said through my teeth, "didn't I tell you we should hide the time machine somewhere safe? And what was it you said? You said, 'no, it'll be just fine here. What's going to happen to it? We'll only be gone for a few minutes."
"Dude, leave me alone," he said.
"Leave you alone? LEAVE YOU ALONE!? After you strand me here in, in... what year did you pick again? 5000 BC? Something like that? What the hell were you thinking? Why? Why 5000 BC, Jimmy? Why not just a few hundred years back, to the 20th century or even the first century, any century AFTER the developement of civilization?"
Now he looks mad. "Hey, it's my time machine, okay? I invented it, and I reserve the right to use it however I please."
"Oh yeah? Well I reserve the right to club you to death and eat your bones when we start to starve! How does that sound, physics boy? And it was your time machine, not is your time machine. I don't think it will be doing much more time travel."
"I still can't figure out what happened here."
"Don't try to change the subject. It doesn't matter what happened, beyond the obvious. Something crushed the time machine. Whatever did it is now gone, and we are stuck, thanks to you."
Jimmy frowned and bit his lip. "Well, it's not like we're going to die here or anything. We have enough emergency equipment to sustain us for the rest of our natural lives, more or less."
"That's just great Jimbo. I'm absolutely thrilled to know I get to live out the rest of my life stuck in the middle of nowhere with you, and only you for company. Unless I do actually decide to club you to death and eat your bones, in which case I'll be stuck here by myself. Ah, to hell with it, I'm going for a walk."
"You're going where?" Jimbo said, but I just ignored him, and kept on trucking into the forest. I needed to get away from him for a while.
After I was gone, he tried to call me a few times, but I didn't want to talk so I just turned off the ringer on my watch. He would probably think I had been eaten by some weird marsupial. Served him right. I was still pretty pissed. Eventually I calmed down though, and called him back. He sounded pretty relived to hear from me. I think he had been crying. I kinda felt bad about that, until I remembered he had gotten me stuck in pre-history. Then I got mad again.
A lot of time passed, and Jimmy and I managed life before civilization pretty well. The biggest problem was boredom. Not a whole lot to do back in 5000 BC. Finally, an idea came to me one day while we were sitting in front of our grotto. I started to laugh.
"What is it?" Jimmy said, "What's so funny?" He could never stand not being in on a joke.
"I have an idea for something to do."
"Well what is it?"
"Let's build stonehenge."
"I said, let's build stonehenge. Come on, it'll be great. We got the anti-grav stuff, it shouldn't be too hard."
"But we can't build stonehenge. We're hundreds of miles from England. Anyway, I don't think we built stonehenge."
"What else do you have to do besides travel to England?" I asked him. "And I think that we did build stonehenge. Man it was such a great joke too. The best part is that we've already seen the punchline, and we haven't even told the joke yet."
"I can't belive you want to build stonehenge as a prank. You are so immature sometimes." I scowled at him. "Oh, what the hell," he said. "Why not?"
So, we built stonehenge. Later, we did the Easter Island heads. Those were fun too. Laughed our asses off the whole time, thinking of all the television specials where they tried to build these things using primitive tools, and the nuts who speculated about alien intervention. We actually had fun, and sometimes I even forgot how much I missed my home. Jimmy wasn't that bad of a guy really. Very smart, and nice, just a fuck-up. Then one day, while working on the pyramids, one of the anti-grav pods broke and Jimmy's head was crushed under a huge brick. From then on, I worked alone (well, until I met my pet orangutan, which I named Jimmy II, but that's another story). Anyway, Jimmy's death sort of took the fun out of the projects, but I must say his bones made a lovely stew.

Note: The timeline in this is entirely random and is not intended to correlate to the actual dates of construction of any weird objects, such as stonehenge.