A Covenant attack on the planet Sedra unveils a plot to destroy humanity. An ONI team and Sedra military staff must work together, despite their differences, to uncover the location of the element and prevent it from being used again.
The team continues to move as quickly as possible to the ship. Losing officers left and right, they become beset by danger not just from their environment, but also from within.
The team of Sedran and ONI officers arrives on the segment of Halo destroyed by Master Chief. An unexpected complication arises, causing them to adjust their plan.
The unexpected complication forces the team to dump a large part of their advanced technology. Can they make it to the ship before they run out of air, or worse, before they are attacked again?