Invasion Books in Order

Invasion is Holmes's big alien-war trilogy, and it begins from a brutal premise. Earth already lost. Humanity did not meet the enemy in some glorious first-contact moment and rise to the occasion. It got beaten from orbit, bombarded, occupied, and shoved into the dirt. By the time Resistance starts, civilization is wrecked, the enemy holds the high ground, and the people still willing to fight are scattered, hidden, and badly outmatched.

That lost-war beginning gives the whole series its shape.

The first book follows General David Warren, once one of Earth's best commanders, now living quietly with family and trying not to draw the occupiers' attention. When strangers arrive, his careful retreat begins to unravel, and the dormant resistance starts to move again. Holmes uses that setup well because it keeps the story close to both strategy and daily survival. The problem is not just how to win a battle. It is how to rebuild a chain of command, revive trust, and convince exhausted people that taking up arms again is worth the cost.

Day of Battle opens the war back up. The resistance stops hiding and starts gambling on liberation. Holmes broadens the cast and the theaters of action, following regular soldiers, armor crews, special operations teams, and the people trying to survive the opening twenty-four hours of a campaign that could either save humanity or finish it off. Tanks duel alien armor, uprisings flare, and battles spill into orbiting stations as the hidden war becomes an open one.

Then Total War pushes everything outward and inward at the same time. The campaign to liberate the Sol System becomes a test of endurance, not just courage. Earth's last starship attempts impossible odds. Marines fight for the West Coast under naval guns. Armored columns roll through Texas. Civilians have to figure out what sudden freedom even means after a decade of occupation. And at the center of it all is the idea that the first day is never the hardest. The hard part is what comes after, when people are tired, plans fail, and grief starts to pile up.

The setting stays grounded despite the scale. These books are full of starships, orbital bases, tanks, Marines, and plasma weapons, but Holmes keeps the focus on the soldier's-eye view. You spend time with crews, squads, and field commanders making ugly decisions with incomplete information. That makes the series read less like abstract space opera and more like a hard-fought campaign history from a future war.

If you like military science fiction that treats occupation, resistance, and combined-arms warfare seriously, Invasion is very much in that tradition. It is not about wonder. It is about taking back ground. The emotional engine is not discovery, but defiance. Humanity is outgunned, exhausted, and late to its own rescue, and the books ask whether that is still enough to matter.