From Halopedia, the Halo wiki
Originally part of the Covenant fleet, the ship was taken by the Sangheili during the Great Schism. After an alliance was formed with the UNSC, the ship's mission was going from system to system, trying to reestablish communication with colonies cut off by the Human-Covenant War. The ship's crew came to include humans they had picked up from those colonies. In 2553 they reached the system where Losing Hand was, initially thinking it barren; however, the Huragok known as Slight List convinced the crew to survey the system. They discovered the downed remains of the UNSC Dark Was the Night, a military cargo tender that had crashed one year ago on the planet after being damaged by a Covenant attack. Major Kyle Stallock, who was stationed aboard The Lookout, updated Dark Was the Night's crew on everything that had happened since their crash. The local population and the ship's crew were offered a way off the planet; some accepted while others remained.
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