When I first picked up Afterparty, I thought it was going to be a story about near-future drug trafficking. And it is, up to a certain point. Lyda Rose (named after a song in The Music Man—Gregory was “in the musical in 7^th grade, and I memorized all the songs”) and two mentally disturbed friends search for the new manufacturer and distributor of a dangerous smart drug that she helped to invent several years ago. Given the recipe, just about anyone can make designer drugs in Gregory’s near future: “If you come up with something like a 3D printer, and precursor chemicals, in principle it can be done; it kind of is almost inevitable.”

But this particular drug, called the Numinous, has a really unique property: It makes you feel as if God is watching over you with love. If one overdoses on it, as Lyda has, one gains a permanent godlike hallucination (in her case, an angel named Dr. Gloria). Consequently, the drug plot serves as a vehicle to explore the concept that faith in a deity is hardwired into the brain.

“I am a materialist and I actually think that is what’s going on,” Gregory explains.  “I don’t think there actually are gods: We see the same neurological effects in believers as in epileptics [who have what they perceive to be] religious episodes. If you can get this from epilepsy, there’s probably a neurological explanation, not a spiritual one. Some say that when the brain lights up [in those areas], that’s when God’s contacting us. You can’t really disprove it, but the evidence is against it.”

But at the same time, Gregory can’t help but be intrigued by the concept of faith. “I grew up southern Baptist,” he says. “I can’t write a paragraph without seeing Jesus in there.” He also explains a great deal of his characters’ backstory in the form of parables. “There was something about the idea of parables I liked. I needed to get that information out, and I liked the format.”

While faith can drive fanatics to do some evil things, faith can also be a positive force, even if the focus of one’s belief doesn’t really exist, or is actually another aspect of oneself. “Lyda is a much better person with Dr. Gloria, her angel, than she is without her,” argues Gregory. “And why shouldn’t you listen to another part of you, especially if it makes you a better person? I do this all the time—I have arguments with myself, have arguments with people who are dead. It seems a valid thing to do.”

Lyda is a scientist who knows perfectly well that Dr. Gloria is a figment of her drug-induced imagination, but nevertheless interacts with her and wants the angel in her life. I wondered if it were possible for logic to overcome faith. “I think you can, over time, convince yourself that looking at the evidence, maybe that the religious tradition you grew up with doesn’t make a lot of sense,” Gregory responds. The next step is to consider “Is there a way I can lose the nonsense and keep the good stuff? Even people who are atheists can have the same feeling of the numinous. Carl Sagan said he felt that when looking at the vastness of the universe. The numinous feeling isn’t bound to any tradition. The task is to interpret the experience. The numinous is not just the feeling that you’re in touch with something outside yourself, it’s the feeling that’s it’s real. It’s really hard to argue against it. There’s no logic that can break that down, especially if it makes you a better person.”

Gregory compares the experience of the numinous to that of love: “Even though love is chemical, it’s still valuable.” Loving one’s children is a biological imperative that helps your genetic pattern survive, he notes, but that doesn’t mean that loving one’s children isn’t a deeply profound and wonderful experience.

Ultimately, though, Gregory intended the book to make “the point that our brain is lying to us about a lot of things. There are a lot of problems with free will.” Rather than having a basis in reality, people have “more a feeling of free will, a feeling that there is a contiguous self behind your eyes. There’s almost no evidence for that. You don’t get a consciousness without a body. But I function every day as if there’s an essential self of me.  Even if that’s an illusion.” 

Amy Goldschlager is an editor, proofreader and book/audiobook reviewer who lives in New York City. She has worked for several major publishers, and has also contributed to the Los Angeles Review of Books, Locus, ComicMix and AudioFile magazine.