==Ecology==
[[Image:Tizca.jpg|thumb|right|[[Tizca]], capital city of Prospero before its destruction.{{Fn|12}}]]
At least one indigenous species on In the time of the [[Great Crusade]], the world of Prospero beyond Tizca was known to have been hostile a lush, verdant paradise. Its landscape featured vast forests, wide open plains, crystal-clear rivers which flowed through its mountains, and extremely dangerous to human the Prosperine oceans teemed with biological life. Beneath the world's ventral mountain ranges, the psychics of Tizca built massive hydroponic gardens.{{Fn|2d}} The surface of Prospero was abandoned by civilization, however, and was dotted with the remains of a long-dead culture. Empty cities, made up of hundreds of skeletal frames of iron and stone, were overgrown with forests and vines and palaces overrun with wild beasts.{{Fn|2e}} After the majority of the planet's population was annihilated by the [[psychneuein]], the world became unsafe for life beyond the confines of the psychically-protected Tizca. Thus, the world outside Tizca's walls became known as '''The Desolation of Prospero.'''{{Fn|2a}}{{Fn|2e}} Tizca's natural environment was warm, nestled amongst mountains and an ocean bay, and featured a river running through Old Tizca, suggesting a Mediterranean climate. Techno-psychic arrays built into the mountains of Tizca were used to reliably predict and control the weather's climate.{{Fn|2f}} The psychneuein, an indigenous species commonly found on Prospero, was a major threat to the early settlers of Prospero . The [[Thousand Sons]] theorized that, thousands of years ago, a warp-event triggered an explosion of uncontrolled psychic potential within Prospero's population, which in turn drove the pscyheneuein into a feeding frenzy, ultimately destroying almost all sentient life on Prospero. The only survivors fled to, and fortified, Tizca, the last outpost of the planet's civilization. Tizca and its citizens continued to thrive, thanks to their ability to harness [[telekinesis]] shields that kept the psychneuein at bay.{{Fn|2d}} The psychneuein continued to present a problem to the inhabitants of the world that would venture beyond the protective wards of Tizca all the way up to the end, when the planet's entire ecosystem was destroyed by planetary bombardment.{{Fn|2e}}{{Fn|2c}}
The psychneuein reproduced by implanting eggs into a host's brain psychically. An infected host would have no idea they'd been implanted until the eggs began to grow, causing severe pain and ultimately, death as the eggs hatched. On only one known occasion has a victim been successfully cured of the implanted psychic eggs. An archaeologist, living in Tizca, had been implanted while outside the city on a day trip. She later collapsed and was taken to a hospital where a team of highly skilled Thousand Sons Astartes were able to use their powers to remove the eggs from her brain in a form of psychic surgery.{{Fn|2}}
*{{Endn|1}}: [[Codex: Eye of Terror]], {{Cite Marker End}}
*{{Endn|2}}: [[A Thousand Sons (Novel)]], {{Cite Marker End}}
**{{Endn|2a}}: Chapter 22The Thousand Sons / Into the Desolation
**{{Endn|2b}}: Chapter 31
**{{Endn|2c}}: Chapter 27
**{{Endn|2d}}: Chapter 16 New Order / Tuition / Fresh Summons
**{{Endn|2e}}: Chapter 17 The Desolation of Prospero / The Fallen Statue / Fresh Summons
**{{Endn|2f}}: Chapter 17 She was my World / Whatever the Cost / The Price
*{{Endn|3}}: [[Scars (Novel)]], {{Cite Marker End}}
*{{Endn|4}}: [[The Horus Heresy Book Seven - Inferno]], pg. 33
