The Fire Seekers (Book One of the Babel Trilogy) is now available as a hardback, paperback, e-book, or audiobook from Skyscape. It's a thriller about the origin of civilization, the meaning of life, and who's trying to wipe us out, among other things. It will seriously mess with your head. "An erudite thriller." (Kirkus Reviews). See hundreds of reader reviews here.
The Truth About Constance Weaver is a mystery about obsession, art forgery, madness, and murder. It's now available in both paperback and e-book formats... and yes, I know, the e-book is cheaper, but the cover is a key part of the story, and rather nice to look at, and e-books cannot yet handle letters in a beautiful, evocative eighteenth century typeface. So buy the paperback. (Or buy the e-book!)
Emperors of the Ice is now available both in the original hardback (with four maps and over 70 photographs) and as an e-book. It won both an 'Outstanding Book' designation from the National Science Teachers Association and a Washington State Book Award; reviewers have described it as "an enthralling tale," and "so gripping you will not want to put it down."
You Are Here: A User's Guide to the Universe is a short tourist guide to absolutely everything. It's now available both as a paperback and as an e-book.
You can find notes on some work in progress here.