Earth Under Siege - Rachel Aukes

First contact may be our last.

On a dark world far from our home, an epic war started a chain reaction, sending two alien races on a collision course with Earth. Secret battles wage on our soil, brewing a war that could change the face of humanity forever. If we can't prevent an alien armageddon, we'll find ourselves fighting forces with technology thousands of years more advanced than ours. The war is on, and time is running out. . . 

A cataclysmic tale of first contact told in three acts: Collision, Implosion, and Explosion.