Well, let's put it this way: In 2005, a freight train derailed in Graniteville, South Carolina, causing one of its chlorine tanks to burst. Five thousand people had to be evacuated from the area, with hundreds requiring medical assistance, and nine died from exposure to the gas. That's the stuff Rick has to haul during some of his runs. It's almost like having to carry a shipment of Rathtars.
"Uh, I think some of the 'gas' might have got out of its cage."
But for all Rick knows, he actually might have hauled the occasional alien every now and then because of his dealings with men in black. "I remember a time when I got to work and was greeted by a nice gentleman in a black suit and sunglasses. I was given a manifest that was entirely blank and was told to get everything together and head for Indianapolis, and to not stop under any circumstances. A helicopter followed us the entire way. Never found out what was in that one."