Empties is very noir in tone, something Hitchcock might have cooked up. Although it's a contemporary setting, the story could just as easily have been set in the 40s or 50s, and actually might have benefited from the shift.
When the first "empty" corpse is autopsied, the coroner barely thinks a body with a missing brain is worth mentioning (because he assumes it's a prank), and mentions they only did the autopsy in the first place because they were bored. I'm no legal beagle, but my understanding is that if the cause of death is unknown, as it would be for a body found on a park bench, an autopsy is required by law. At least, it is where I live, and I'd assume that even if other places fluctuate on the matter, they'd still check out a man found dead in those circumstances, especially considering the bits of fleshy material found on the fence near where he sat. I'm pretty sure a corpse missing a brain, especially one with no indication how the brain would have left the skull, would be the talk of the office. They might well suspect a prank, but it's unusual enough to intrigue more than just one loner detective.
On the other hand, I really enjoyed the introspective viewpoint of Benek. Like most of us, he questions himself, his life, everything, while doing his mundane activities, but instead of skipping over, the narration of Empties delves right in there. As a result, his slow descent into what he suspects might be insanity but isn't sure is enthralling and poses some very potent questions.
Dierdre was far less complex, one of those people who thinks she should be able to do whatever she wants. She's a dark, twisted little soul, and while she has some interesting potential, I'm not sure all of it got truly explored.
Readers should be warned there's a part of the novel wherein Deirdre drugs Benek, handcuffs him to a bed, and repeatedly rapes him. The scenes aren't graphic, but rape is rape, and neither character seems to recognize it enough to call it what it is.
The book is dark and wonderfully moody, with some great imagery and a very different protagonist, but ultimately the idea that Benek was the only person who'd think twice about a series of empty-headed dead bodies drew me right out of the story.