After Earth A Perfect Beast. Michael Jan Freidman, Robert Greenberger and Peter David. 2013.

After their exodus from Earth, the last humans settled a remote planet: Nova Prime.

Conner Raige's ancestors were on the front lines of victory against the Skrel, a long defeated enemy. Now he is one of the United Ranger Corps' most promising young cadets, despite his brash confidence and tendency to act on instinct.

But when the Skrel return, a deadly ground war will test him to the limit.

Only this time, the Skrel have brought a secret weapon: ferocious killing machines designed to eliminate humanity from Nova Prime... and the universe.