Poul Anderson,
The Golden Slave
“ Would it not be most honorable of you to release them from whatever vows they gave you—even command them to depart?""He is our king," said Phryne from the darkness. "There are some commands that no king may give."Flavius sighed. "As you will, then. Decurion, seize them!"It was a narrow doorway; only one person at a time could go through. The Roman decurion advanced with an infantryman's long shield to guard him. Eodan waited. The decurion charged in, behind him a pikeman. Eodan smote at the first Roman's knees as the pike thrust for his face. ”
