It is 2553, and the three-decade-long Covenant War that defined a generation has suddenly drawn to a close. Yet in the remotest parts of human space, tensions remain that threaten to overflow into another full-scale conflict. Beneath the surface of the planet Gao lies a vast cavern system renowned for its therapeutic effects and rumored miraculous cures. But now Gao natives are turning up brutally murdered down there - violent acts that happen to coincide with the recent arrival of a UNSC research battalion protected by Spartan Blue Team, led by the renowned Spartan-II Fred-104.
