Fields of Fire and the Frontlines series

Marko Kloos is about to release the latest in his Frontlines series - Fields of Fire (Book 5). I can't get his books for free at library, so I will shell out the $5 on Amazon for it. If you've not read the others, he's got them on sale for a dollar each. Obviously, he's trying to get you hooked, so you'll spend the big bucks like me.