Long ago there lived a nasty, quick-tempered little drunk named Jack. After years of drinking, fighting, and all-around bad behavior, Jack stumbled into a pub on All Hallows' Eve. He proceeded to get "in his cups," so much so that he was actually facing death. As his life was slipping away, the devil appeared to claim his soul. True to his nature, Jack begged for one more drink before he was taken to hell. The devil agreed and Jack ordered a pint of beer. And wouldn't you know it, Jack didn't have the money to pay for his final drink. Here's where things get a little odd. Jack asked if the devil would transform himself into a sixpence piece to pay for the drink. And the devil agreed. (How this guy became the ruler of hell is beyond me.) The devil turned into the sixpence and Jack shoved the coin into his wallet, which had on it the sign of cross. The power of the cross trapped the poor devil.
The devil demanded Jack release him. Jack agreed, with the condition that the devil leave him be for a year. For a while, Jack was a better man, a man of moderation and kindness. But soon he was back in the pubs, drinking, fighting, and being generally unpleasant.
After a year had passed, the devil returned for Jack's soul. And get this: Jack asked the devil to climb up an apple tree and get him an apple for the trip to hell. When that gullible old devil agreed and climbed up the tree, Jack carved the sign of the cross into the trunk and trapped the devil once again. Jack released him, on the condition that the devil never bother him again.
Eventually, Jack died. When he arrived at the gates of heaven, he was refused entry due to his mean-spirited nature. He then tried to find a home in hell, but the devil, still angry with Jack, wouldn't let him in. So Jack was forced to wander. The devil threw a burning coal to him, so he could light his way through limbo. Jack took the coal, put it in a hollowed-out turnip, and spent eternity looking for a home in the darkness.