The Nail of Heaven is the northern star that, aside from being the brightest in the night sky (it is sometimes visible in daylight), provides the axis from which all other stars revolve. The Nonmen called it ‘Imburil’, meaning ‘the Newborn’.
In the slot of a hanging ravine, the Nail of Heaven twinkled alone in the endless blue, a beacon of all things high and open…
A final call to those who would dare the nethers of the earth.
One night the star suddenly blazed with a strange, sudden intensity. This waxing lasted a time and then abated. The Cûnuroi could not explain it, but then dismissed it as a curiosity and moved on with their lives. Three years after this curious event, the Incû-Holoinas fell down.
This may mean that the Nail of Heaven is not an actual star but rather a wormhole Incû-Holoinas came through or even a mother-ship with Incû-Holoinas being a drop-ship. The fact that Nonmen call this star 'Newborn' support either of this.