It is a part of Piper's Terro-Human Future History series, and is nearly identical with his 1964 Paratime short story "Gunpowder God", which was later expanded into the novel Lord Kalvan of Otherwhen.
The ten men and five women who represent the total personnel and stockholders of Stellar Explorations, Ltd., are pleased to have found a Terra-like world, but disappointed to find that it is already apparently inhabited by an intelligent race.
Setting up in a field, the spaceship is finally found by an armed Hostigi patrol, led by Princess Rylla, daughter of Prince Ptosphes, and captain-in-chief Chartiphon.
When the Terrans are informed about the political situation in Hostigos, they sign a military alliance with the Hostigi, and begin preparing for war.
The Terrans inform their hosts that the secret of making “fireseed” (gunpowder) is not complicated, and that they will help them build their own powder mills, breaking the monopoly held by the priests of the god Styphon.