Reading his interview in the WSJ put me in a mood for some of McCarthy's dark, murderous and usually disturbing prose.
"Child of God" fits the bill. One of his shorter stories at about 200 pages, I went through it in a day. It reads a bit easier than some of his longer novels, with a bit less of a focus on describing every detail of each and every scene.
Lester Ballard is a man alone. He has been banished and cut off from society, and that frees him to explore all the darkest passions of his mind. Ballard is far from a sympathetic character, but there is an underlying message that judges society for ignoring those that live on the very fringes of a community.