Harbinger of Piety
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Battle of Cleveland
The ship carried at least one Prophet, the Minister of Inquisition. The Prophet was curious about a Forerunner artifact called the Key of Osanalan, which was in fact, fake. It had been made up by James and Ruwan Ackerson when they were young.
Ruwan Ackerson had met the Covenant and told the Covenant that he was actually the key. Confused, the Covenant took the human to the Harbinger. In reality, Ruwan had been implanted with an organic tracker for the UNSC to find and destroy high ranking Covenant officials. The ship's position was subsequently relayed back to Earth Orbital Defense Platform Nassau Station, which proceeded to destroy the Harbinger of Piety with a single shot from its MAC gun.
Harbinger of Piety is first depicted with four forward ventral prongs, as seen on CCS-class battlecruisers in Halo 3. However, the panel showing its destruction depicts it as only having two prongs like those in Halo: Combat Evolved and Halo 2.
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