Unidentified ancilla (Shield World 0459)

"Security barrier breached. High order infection detected. Unidentified alien intrusion detected. Initiating Stage 3 Defense Protocols."

- When enters the Shield World

An Unnamed Forerunner AI was a construct located on the Flood-Controlled Shield World.

History
It is unclear whether it is in charge of the whole Shield World or just the Cleansing Rings. When the went into the underground section, the AI detected a "high order" Flood infection and an unknown alien intrusion. The AI autonomously initiated "Stage 3 Defense Protocols", which included activating Sentinels, cleansing rings, and Super Sentinels to clear away the Flood and the "unknown alien intrusion". Every time the Spirit of Fire approaches a cleansing ring, it will say "Decontamination sequence commencing". It was most likely destroyed with the destruction of the Shield World.

Trivia

 * The AI's voice does not resemble that of any other known Forerunner AI. While AIs like the Monitors have a more natural voice, this construct speaks in a robotic monotone. It's seemingly what could be classified as a "dumb" AI, as it seems to only follow a strict programming and doesn't even take note of the presence of "Reclaimers", as it only refers to them as "unknown aliens".