From Halopedia, the Halo wiki
During the Requiem Campaign, he was assigned to "the Refuge." While he was there he studied Requiem's portal system along with Dr. Ruiz. With the help of Fireteam Crimson, Boyd used equipment at "the Gate" to gather valuable information about Reqieum's portal system, and was able to figure out a way to open a portal to bring Crimson from the Gate to "the Refuge." Shortly after they arrived, "the Refuge" was attacked by Prometheans. When the Promethean assault started he ran to the safe room. Boyd was able to direct Crimson to deactivate equipment which allowed the Prometheans to translocate into the Refuge. When the Covenant attacked "the Refuge" shortly after, Dr. Boyd needed Crimson's help to open the safe room's door.
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