Merciless Pact, is a spare, vicious piece of horror writing. I was very impressed with his collection of fiction, Mayhem, and with this entry, Brown proves that he is just as adept at longer work.
Merciless Pact starts right in on the action: Greg is at home minding his own business when his "friend" comes over, holds him down, and vomits all over him. (This was definitely horrifying but, in my opinion, also pretty fucking funny.)
Nothing goes right for Greg after that. He slowly morphs into an animal only concerned with consuming food and sex whenever he can. He's inexplicably drawn to a sinkhole in the woods, where he encounters a character who is kind of like the evil twin of the Space Coyote from The Simpsons. The only way out of this curse is to make a pact with the evil spirit.
Brown doesn't waste words in this tightly plotted tale of psychological agony. He maps out Greg's descent into madness and never veers from the course. It's dark to the core.
Also, I had a lot of questions to muse on after reading Merciless Pact: How much agency does Greg really have? Are Greg's friends really trying to help him? Is Greg an awful person or just a person? Does Greg just invent the entire thing? (Don't get me wrong -- there's no Fight Club kind of ending here. Nonetheless, I thought this might be the case...)
Anyway, this is a great, fast read. Go pick it up at Amazon for $2.99.