Here, you have to rescue two of the Lamplight kids from Paradise Falls in order for Mayor McCready to let you into the Lamplight Caverns. The best, but most difficult way to do this is to basically start a riot. Kill Grouse at the entrance to get the ball rolling, and kill everyone who comes after you, you'll need to take a lot of chems, and you'll need a hell of a lot of firepower. Get the key from killing Forty, and if you so wish, go and kill Euology Jones in his mansion, he has a scoped 44 Magnum.