From the introduction:
The world was once a primitive land, inhabited by crude, unintelligent life forms. It was a place of harsh and unforgiving extremes. Large portions of land were covered in thick glacial ice, ravaged with vicious storms and unending blizzards. In other areas, volcanoes poured hot lava and poisonous ash into the atmosphere. Between, tiny pockets of humid and hot jungles teemed with savage life and many forms of poisonous foliage.
Into this world came the Old Ones – a mysterious, space-travelling race possessed of immense power and intellect. These beings could mould the very fabric of space and time to their will, travelling unimaginable distances in the blink of any eye in their vast ships. These beings brought with them their servants and slave races, amongst and first of them being the mighty Slann. The Slann were blessed with immense powers of the mind, though but a pale shadow of their masters’ supreme intellect. The beings settled in the teeming jungles, erecting the first and greatest civilisation to grace the planet.