Mundy: Hey guys, check out my arm. I think my arm is trying to write something.
Tam: Logic doesn't apply to any of this.
Mundy: I don't know the rules, now. Do you think there's any chance it might grow back?
Acosta: I don't know. I don't know what to believe anymore.
Volkov: We're definitely not in Kentucky anymore.
Mundy: Kansas.
Volkov: Kansas? Really? Who gives a shit?
Mundy: People from Kansas?
Mundy: What are you talking about, Arm?
Answer: There was no explanation about this but it appears to be more of a plot device to foreshadow future story line events and create suspense. Movies are less concerned about technical accuracy than moving the story forward in an engaging manner.
raywest