It is an evil spirit which continually attacks individuals in the area. This had eventually caused all but those at Paul's ranch to leave the area. It's coming is usually accompanied with a violent sandstorm, also shaping itself like a titanic sandstorm spirit, attacking people and/or animals with his 'claws'. It is revealed that several generations prior, the Dineh held a ritual to summon it into the mortal world, to get revenge on the white soldiers who had destroyed their village and killed their people, just near Fort Crown. However, Yé'iitsoh is indiscriminate, attacking both the Dineh and soldiers. It continues this to the present, attacking any living beings it can reach, an example of which being one of Paul's sheep. After they died, the Dineh summoners try to do their best to ward off Yé'iitsoh from attacking their descendants down into the modern day.
If the player fails to successfully complete the ritual to send Yé'iitsoh back to where it came from, it will eventually flee. The chapter ends with Jodie being given the motorcycle, being thanked for her attempt to stop Yé'iitsoh, but admitting it was ultimately futile. After Jodie leaves, it can be presumed that Yé'iitsoh continues to torment them from then on.
- Yé'iitsoh means 'Big God' in Navajo.
- Yé'iitsoh shares its name with a folk-lore creature, based in Navajo legend.