I had to dig deep to uncover this one completely:
I was listening to a monologue of a guy who kinda looked like a pirate, except he was just a criminal, basically, who was describing how he was going to kill someone he really hated and cut off their fingers and their penis and create a necklace out of them, and he was going to use a steampunk rifle/sabre combo to do it.
When he was done I found myself in my own body (as opposed to that of a disembodied viewer) and figured I should probably prevent that grisly murder from happening. From the window on the second floor I could see the murderer get out of a car, so I rushed downstairs to try and stop him. Only when I got there he was gone, and I couldn't tell if he still had to commit the murder or had already done so. I looked around a little bit and saw that there were bloodied footprints on the ground, so it must have already happened. I then went back in time an hour or so by adjusting the time on my watch to be able to catch him, and then I took a big, heavy, wooden baseball bat, smashed in the window of the car and hit the person inside a few times, enough to make sure they wouldn't be capable of murdering anyone for some time.
At this point, the identity of the person in the car was either my mother or my sister, and my dad might have been the target of the murder, but that was seemingly unimportant. Anyway, I figured that this approach was slightly overkill, so I went back in time again, this time two hours before the murder, and tried to get the rifle/sabre away from the murderer by ambushing her - my sister, in this case. I hit her in the back of the head with the bat once, like hitting a ball with a pool cue, and then took the gun away, but she did put up a fight, and I had to shoot her. My mother exclaimed "I didn't even know that was loaded!" (in English, not Dutch) and I was like "Duh, gun safety" - have you guys to thank for that, I guess - and so, having yet another undesirable outcome, I went back to the point where the murderer was just a little boy with a fancy BB gun. A high-powered, bladed, steampunk BB gun that was capable of killing someone, but nevertheless technically a BB gun which meant everyone else just dismissed it as a toy, even when I tried to convince them that the little boy was going to kill someone with it in the future, but obviously I couldn't do anything about it since it hadn't happened yet. So that was the end.
That was the most coherent dream I've had in a while.