Possible spoilers! If you’ve read the book, this post may be of interest because it contains certain information the characters of the book do not have. The world of New Persia is a real place!

From 70 Ophiuchi B, our sun lies between Orion’s belt and the star Sirius in the night sky.
The physical setting
New Persia is the largest nation on the only continent of a planet orbiting the star 70 Ophiuchi A, which is 16.6 light-years from Earth. 70 Ophiuchi B orbits 70 Ophiuchi A and circles the more massive star every eight decades. The light cast by the binary at its closest approach is similar to our sun at twilight after sunset. The orbit is highly elliptical, and when 70 Ophiuchi B is far away, it dims to the brightest star in the sky. New Persians can always see it in daylight. It rises and sets with the rotation of the planet, and during half the year it rises during the primary night. During this time, the light level on the surface never reaches darkness, and the light level depends on the distance to the binary star.

The orbit of 70 Ophiuchi B as seen from Earth
There are other planets in the star system, but they are not significant yet.
70 Ophiuchi A is a K0 orange dwarf. Its light is dimmer than the sun’s as seen on Earth and appears orange-tinted to humans on the planet. The native vegetation is pigmented a dark purple to take better advantage of the lower light frequency.
The Waste
On the world of New Persia, the native vegetation is exceptionally hardy and drought-resistant. The single continent on the planet has a large interior where almost no rain falls. Temperatures in the interior can reach more than 150 degrees Fahrenheit, and no Earth life can survive there.
Because of the seasonal heating of the interior and the relative coolness of the oceans, monsoons develop. Hot, dry winds blowing out from the interior alternate with cool, wet winds blowing from the sea. The New Persians live in the monsoon zone between the southern ocean and the central Waste. They benefit from steady, predictable rains that support agriculture.
Seed Storms
When the rains fail, a climactic event called a seed storm begins. When the interior does not receive the scant amount of rain it gleans from the last gasps of the monsoon, the native life spawns. Plants produce seed pods the size of Earth apples. The pods extend long threads meant to catch the wind and carry the seed aloft. When the dry monsoon winds come again, they blow out of the bone-dry interior in the form of sandstorms. The sandstorms bring seed pods with them. In an average dry year, the storms don’t go very far out of the Waste and carry few seeds south. The winds are only a significant threat when they are both powerful and bring the seeds of many native plants. On average, this happens twice a century. When several dry years coincide with a particularly strong monsoon, the results can be catastrophic.
Bad Seed
The seeds carried south inside the monsoon dust storms ride high in the air. They fly until their threads are damaged, or the storm weakens and deposits them on the ground. When they touch the ground or are buffeted by the wind, the seed case bursts and sprays a flammable liquid over the seed husk. The dry shell is easily ignited by static electricity within the sandstorm. Now burning, the seed will spread fire wherever it lands. The seed pod still trails the threads that keep catching the wind and dragging the seed across the ground. Because the native plants spawn during droughts, wherever the seeds land is likely to be dry and ready to burn.

Seed Storms are even worse than California wildfires.
The seeds themselves are fire-resistant. They sprout in the ash left by the passing of the storm, and a devastated area is soon home to thousands of fast-growing native plants. Because the soil biochemistries of native and Earth plants are incompatible, the seed storm leaves vast swathes of land poisoned and no longer suitable to support human life.
After the Storm
It can take decades to recover from a seed storm, and some areas are lost forever. At times in the past, colossal seed storms left entire human civilizations under layers of ash. The technology available to people on the planet in the thirty-fourth century AD is less advanced than the Founders possessed. Several massive storms have set back human progress and limit humanity’s ability to colonize the entire planet. The current level of technology is equivalent to Earth’s in the mid-twentieth century.
Seed storms threaten human civilization on the world of New Persia. Nations can fall before a storm. Only vast empires can survive in the long term because they are more difficult for one storm to destroy. Storms still have consequences. The consensus among historians of the Azanian war is that New Persia defeated Azania because of a seed storm that devastated the interior of Azania. It was not because of New Persian force of arms.
What causes the largest seed storms on the world of New Persia? It turns out that there is a cause, and it is predictable. The characters of New Persia: Before the Storm don’t know that, and the exact mechanism is something for them to discover when the time comes.
This is really well-thought-out information! Very interesting!