The Siege Above Mars. The Last Battle of Earth, #4

Earth survived the first invasion. But the war is not over. After the E. S. S. Guardian destroyed the Veyran command ship, humanity believed it had earned a moment to breathe. Cities were burning, families were grieving, and the world was still wounded-but Earth was free. Then a final alien signal reaches Mars. The surviving Veyran fleet has regrouped above the red planet, where General Sareth begins building a slave gate powerful enough to move millions of humans off Earth.
If the gate opens, humanity will not simply lose a battle. It will become property. Captain Elena Cross must lead the wounded Guardian into space and defend Mars before the siege becomes a doorway to human slavery. But Mars is not just a military target. It is a fragile home of domes, miners, pilots, greenhouse children, pressure tunnels, and ordinary people refusing to kneel. Outnumbered and hunted, Elena and her crew must face alien warships, deadly traps, betrayal, sacrifice, and the terrifying truth that the Veyrans are learning from every human victory.
To save Earth, Mars must hold. And if the Guardian falls, the road to slavery opens.