The invasion of the brutal race, the Deamhan, commanded by their leader, Caochladh, has ravaged Earth. In the midst of the war, Major Luke Reiber lost everything. His family, his friends, and his career and has hidden away in disgrace, lost to his grief. When a figure from his past offers him the chance to travel back in time and save all those he lost, he knows that there are rules he has to follow, but there will be grave consequences if he fails.