The remaining protoss gathered for a last stand. They sought to hold long enough to complete the archive, hoping to prepare future civilizations against Amon.
The archive is a unique structure. Protecting it from Amon's forces until it retracts into the ground is an optional objective. It is invincible afterwards, and once it is sealed, three decals can be seen on top of it; that of the Daelaam, the Akilae Tribe, and what appears to be a stylized Purifier decal.