Level 6  (Ledbetter, 2020) - This text is only available as an audiobook. It's a sequel to Level 5, which similarly was only in audio format in what is now listed as the Killday series. I met the author, William Ledbetter, during a convention in Houston a couple of years ago. We were both panelists for writing discussions. One thing I love about Ledbetter's work is the science fidelity at play. Of course, the stories are fiction, but the technology that defines the world he puts readers in feels like it is only a short leap away. In Ledbetter's vision of the future, AI has proliferated, as have the use of nanobots, both of which turn out to be to the detriment of mankind.

Level 6 takes place roughly fifteen years after the first installment and follows the path of a college-age woman we met briefly in the first book as a little girl. She is the daughter of a prominent character from the first who (spoiler) died at the end of the first book. So this woman, Abby, has been an orphan. 

I really enjoyed this story. I already loved the world and the technology affecting it. Ledbetter has flushed it out very well so that readers understand how it came to be, and we can relate to how humans have become so reliant on it. In Level 6, we get to see the fallout from the first book's events and how humanity tries to put itself back together after a catastrophe. We get a love story subplot that takes some turns I didn't expect. Like the first, we get to see a political struggle for power that turns deadly. However, the thing I like most about this one is where the story takes its namesake. 

The AIs in this world are categorized at levels, with level 1 being the most basic, perhaps like what we really have today, and so on. The Level 5 AIs are sentient, free-thinking, and mostly self-directing. The exciting aspect is that some of these Level 5 AI's want to produce a Level 6, they want to create an offspring or an evolution, so to speak, that is better than themselves. I think that makes them even closer to humans. People, at least those who have children, tend to think of making life better for their offspring. We want to give children opportunities we didn't have. Much in this sense, so do the AIs in the story.

There's plenty to find fascinating, like rouge nanobots building eavesdropping devices right into a person's body, and if need be, building an execution device right inside your body as well. Just cool possibilities to think about, but the humanity Ledbetter endeavors to explore is even better. Why we would build these AI, why we'd rely on them so much, why some people would fear them, why some would treat them like gods, and how they would evolve to be like us. All these themes are deliciously on the table.