Mucho Mojo: Mucho Mojo (HB) by Joe R Lansdale
When Leonard Pine's Uncle Chester dies, Leonard is not expecting to inherit. But it seems that $100,000, a house and its contents have all been left to him, along with a mysterious key which doesn't seem to fit anything in the house. However when Leonard and Hap move in to repair the old place, they discover a crack house next door and, far worse, the skeleton of a child, hidden in a trunk underneath the floorboards. It seems that Uncle Chester's life was not exactly the way Leonard and Hap imagined it to be...