In the days of sailing ships "hell" was the term for the bottom of the boat; the hottest, dankest, smelliest area. To "pay" described mopping tar in "hell" to help keep the ship sea-worthy. It was also the worst job to have handed you. Thus the saying, "you'll have hell to pay" or rather you'll be sorry if you don't do as I say.
Clean your room or you'll have hell to pay!
by Burt Trmlicker December 20, 2008