I have spent many hours that might have been more productively spent weeding a garden thinking about the nature of good and evil. Like many of my species, I have questioned why there is evil in the world. (Presumably there is evil in the universe as well, but my experience is limited.)

I was brought up Episcopalian (Catholic Lite). The Judeo-Christian explanation of good and evil makes perfect sense until you start asking questions: “If God is good and all-powerful, why doesn’t He just get rid of the Devil and make everything wonderful?” That’s when Father Cummins would narrow his eyes, purse his lips and croak something like, “The Devil is there to test your faith. Copy this 500 times on the blackboard.” A few more answers like that, and I learned to shut up, which was what Father Cummins wanted in the first place.

I no longer believe in the Devil. Or Santa Claus. Or any number of other things I believed in as a child. But there are things in the world that I can only classify as evil, whether or not there is an actively evil entity behind them. Much of what I perceive as evil is unnatural: murder, kidnapping, cruelty. But there are so many cruelties that occur in nature. What a mother wasp does to nurture her babies is a living hell to the spider she catches. Is it evil if it’s a behavior an animal has naturally evolved to survive? If I were on the receiving end, I don’t think I would have any doubts about it, so maybe it’s all a matter of perspective.

And then there’s deliberate evil, committed with knowledge of the consequences and executed without the excuse of needing to do it to survive. As a child of the 1950s, I believed the brightly illustrated textbooks that told me about the beauty and natural riches of our great nation. Imagine my shock and astonishment when I discovered in my teens there were rivers so polluted that they periodically caught on fire. If you fell into the Potomac, you had to rush to the hospital for treatment because of the sewage in the river.

People were knowingly pouring poisons into the air they and their children breathed and into the water they and their families drank. I found this gobstoppingly unbelievable—and still do. Doesn’t this kind of behavior qualify as evil? Why would anyone in his or her right mind do something like this?

There’s been some progress in curbing various forms of pollution, but there are still those who try to game the rules and get away with it. It seems to be a constant battle to retain clean air and water standards, or to keep endangered animals on the protected species list. (Of course, a lot of them have fallen off the list because they are now extinct.) And don’t get me started on the climate change deniers, or the people who want to build more nuclear power plants. (Chernobyl. Three-Mile Island. Fukushima. Does anyone remember?)

My bemusement over these issues was one reason I wrote “The Obsidian Mirror.” I tried to imagine what would influence people all over the world to deliberately ignore the damage they were causing to the world, the environment, other people, their families, and themselves. It’s a fantasy novel, so the driving evil is the ancient meso-American god Necocyaotl (which means The Obsidian Mirror or The Smoking Mirror in Nahuatl). As the novel is set in present-day Silicon Valley, I devised a modern, technological way that he could disseminate his nefarious influence worldwide. (No spoilers; I’m not going to tell you how he does it.)

In contrast, my heroine Sierra loves nature and likes to hike and camp. She doesn’t want to see the wild places spoiled and destroyed. Not being stupid, Sierra is reluctant to take on an ancient, evil god—but she does.

I tried hard not to get preachy about the environment. There are lots of dramatic clashes between the camps of good and evil and a romantic subplot. And humor. I’m a firm believer that you can’t convince anybody of anything unless you season it well with humor. But the underlying theme of the book is doing the right thing for the world.

Just my little stand against the forces of darkness.