21 books • 4 series
Book #3: The Extinction
Book #1: Behemoth
Book #2: Hyperspace War
Book #2: Leviathan
Book #3: Gates of Hell
Book #4: Tears of the Sun
Book #1: Hyperspace War: Behemoth
Book #2: Hyperspace War: Leviathan
Book #3: Hyperspace War: Gates of Hell
Book #4: Hyperspace War: Tears of the Sun
Book #1: The Fossil