UNSC Edge of Umbra
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In 2503 the Office of Naval Intelligence discovered that Lyrenne Castilla, the second wife of then-Captain Preston Cole, was a high-ranking member of the insurgency. ONI suspected that Cole may have unknowingly or even actively collaborated with Castilla, and as such decided to have him returned to Reach for debriefing. Cole was confined to his quarters aboard his ship, the UNSC Gorgon, until the Prowler Edge of Umbra arrived in the Lambda Aurigae system. The Umbra then transported Cole to Reach.
The name of the Edge of Umbra is likely a reference to the darkest part of the shadow cast by a celestial body. An observer positioned in the umbra of a planet or moon is said to experience a total eclipse.
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