This in another case of... The Curse of the 2H Pencil! I tried to adjust the levels but to no avail.
I'm posting this not because I think it's a great sketch or that I've run out of other material (I've got plenty more) but it shows how things sometimes start and then just...
I found this the other day while I was looking for something else and the simplicity of the line just struck me.
There's faint traces of a word balloon to the right of ZONE'S head, all that I can make out from the original drawing is, TRIPPING IN NORTH... and then just the letters A and R. Your guess is as good as mine.