After the initial setback of Cortana's return, her affect caused Captain Lasky of the UNSC Infinity to order any on board ship AI to enact Cole Protocol. As AI Hera initiated a jump to Slipspace the crew of the ship Spirit of Hope went into cryo stasis with Sierra-G145, one of the last Spartan IIIs, on board. It has been 4 years since last contact with Gamma company or the UNSC. The war with the Covenant factions and Cortana still grows, but Hera doesn't know where she's landed.