Set between the events of Halo 4 and Halo 5: Guardians, Halo: Nightfall tells the dramatic story of legendary manhunter Jameson Locke (Mike Colter) and his team as they are caught in a horrific biological attack while investigating terrorist activity on the distant colony world of Sedra. Led by Locke, agents from the Office of Naval Intelligence (ONI) are forced to coordinate with a Sedran commander with a remarkable history and deep-rooted mistrust of ONI. As the plot unravels, they’re drawn to an ancient, hellish artifact where, forced to fight for their survival, they begin to question everything and, ultimately, have to choose between their loyalties and their lives. Agent Locke is a new character in the Halo universe playing a major role in Halo 5: Guardians.