Opus X: Fleet of One Books in Order

Cyrus and Kat postpone their search for Navigator secrets to investigate possible alien infiltration on a colony world. Entering insurrectionist territory exposes threats beyond the assassins pursuing them, as ruthless opponents prepare to sacrifice whole colonies.

Kat and Cyrus use ancient artifacts to locate an alien threat before it awakens, while clone assassins and returning weapons spread danger. Humanity needs a defensive alliance, but forging one may prove harder than their discoveries suggested.

Kat and Cyrus are sent deep into alien territory to uncover secrets on a treasure planet amid rising sabotage and terrorism. A new infantry squad distrusts Cyrus's civilian role, threatening the teamwork their dangerous mission requires.

An ancient alien artifact discovered on the frontier draws xenoarchaeologist Cyrus and former soldier Kat into a dangerous investigation. Amid human betrayal and government suspicion, they face competing interests determined to exploit technology they barely understand.

Cyrus and Kat face new uncertainty as their artificial intelligence, Jade, evolves after their journey into Empty Space. A missing human warship sends the fleet into a rescue mission against an enemy they did not expect.

Cyrus and Kat confront an enemy seeking to open ancient interdimensional prisons, threatening millions of lives. Their team's mission to escort an alien ambassador adds diplomatic tension as they seek the alliances needed to resist the danger.