In a future dominated by the church and defended by the sword, one piece of forbidden technology may change all the rules.

Adrian of Tarsus is a veteran Knight Hospitaler. His adopted daughter, Mariel, serves as his squire, and together they travel the galaxy aboard the ancient merchant ship Miranda. Adrian uses his position as a church enforcer to provide cover for his real quest: A cure for Mariel's mysterious and painful illness, which worsens every day.

Trouble is, Adrian's certain the cure requires Machina Infernus, heretical technology forbidden by the church, and not even a knight can hide from the holy office of the universal inquisition.

When the Miranda's crew are ambushed while acquiring such an object, Adrian turns to Sabine Adler, an old flame and specialist in Machina, for help.

But once on the planet Bethany, Sabine's home and the seat of Christendom, assassins come out of the woodwork and everyone seems to want Adrian's relic - mercenaries, cultists, thugs, politicians, even the inquisition. Most troubling of all are a pair of unusual nuns who claim to know the location of the lab where the relic originated, and the fact that one of them bears a striking resemblance to Mariel.

Adrian has survived years of galactic crusades and church politics, but these women may be the death of him.