How far can the devil's trap reach? (spoilers for season 1)

Question

In season 1 episode 22, the devils trap is introduced: a magical ward that traps demons withing its circle. It is used in the same episode to trap Meg (possessed):

What confuses me is that she was trapped in it when it was painted on the ceiling and she couldn't leave the circle, so how far would the magic work? Like how far underground would that work? Or if it was painted on the ground, how high could it go? (For example, what would happen if a demon got caught while in an air plane? or could it? are there any examples of anything like this happening in any canon sources?)

Answer 1

So far, we've never been shown the extent of a demon trap, other than knowing that it appears to work in all three dimensions for any "nearby" demons.

We have seen demon traps used in a number of ways, including:

• Painted on the floor (including hidden by rugs)
• Painted on the ceiling
• Painted on the inside of the roof of the trunk of a car

The general idea is that the demon trap projects a "cylinder" of magical energy, perpendicular to it's plane. Once a demon is fully within the cylinder, it's physical body cannot get out. As far as I know, we've never seen a demon trapped in a demons trap more than one floor away.

However, we have seen demons get out of traps a few different ways other than walking out; in particular:

• Demons have smoked out of their bodies to escape the trap, implying that the trap does not extend all the way to hell.
• Demons have been forced out of the trap by others, which makes me suspect that a demon being moved though it by a car, plane, etc. would just move out the other end.