Following a human-Covenant war, new threats emerged: the Flood, the Forerunners, and the Banished. A crucial mission arises: delivering a serum that could end the conflict. Spartan VI Megan 601, a rookie, is tasked with this mission. She is partnered with a pilot (you) who was delayed and is now involved in the mission. Together, you must navigate a warzone to deliver the serum.