As the title implies, "A Pair of Aces" is broken up into two parts. Aside from having the author in common, there is no obvious reason for the match up of the first half of the book and second half of the book. It's a Joe R. Lansdale book, though, so I'm willing to scratch my head, but keep on reading.
The first part of the book is made up of three shorts stories and a screen play. The theme tying all of them together is Mr. Lansdale's character, the God of the Razor. As you might expect from stories with such a character, they're all tales of horror. While you'll find plenty of amusing dialogue and inspired similes, the tales suffer from the same weaknesses of most horror stories. In general, there is no way to permanently stop the evil. If one pseudo-possessed nut job croaks, by the end of the story a new person falls under the spell of the GotR and we the reader know the cycle will repeat. Of the four pieces, I enjoyed the screenplay the most, which surprised me. It might be due to the fact that I've never read a screenplay before, or it may be because it was made up almost entirely of dialogue and Joe R. Lansdale is at his best when putting words in people's mouths.
The second part of the book was made up of a novella called "The Magic Wagon". While there is some hint of mysticism in the story, it's mostly about a boy in East Texas, who loses his parents and joins up with a traveling pair offering snake oil, trick shooting, ape wrestling, and peaks at the supposed corpse of Wild Bill Hickok. The story is equal parts humor, tragedy and violence, often with all three tangled up with one another. I wouldn't put it up there as high on my list as "The Thicket", but it was entertaining and had a few twists in it I didn't see coming.
All in all, I could have done with the two parts of the book meshing better, and with the title of the story being what it is, I would have liked something more akin to "The Magic Wagon" to take up the space of the first part of the book. Due to this being a mixed offering, and me not overly thrilled with a set of horror stories that have few surprises, I'm going to give three stars to this one.