Acting on an impulse Jim picked up a hitchhiker. They chatted pleasantly enough and then the hitchhiker said, “How do you I’m not a serial killer?”

“Oh. I’m pretty sure that you aren’t.”

The hitchhiker was surprised at how calm Jim was and said, “Well why are you so sure?”

“The chances of there being two serial killers in one car is pretty remote isn’t it.” And then Jim smiled his sinister smile.