Geeks and mysteries and parallel universes, oh my!
Interesting world(s), and I really like Marlowe and Sage as main characters, they work well together. Bonus points for a geeky hero (yay!). The combination of mystery, sci-fi and a bit of a romance absolutely hits the spot for me. :)
I had one minor issue at first, though: I found the change of POV a bit confusing - not that there were four character POVs, but that they changed between 1st and 3rd person, depending on whose POV it was.
All in all a very enjoyable read, the rest of the series is now on my wishlist. :)