Teana's Travels Book 28: Requiem

Fresh from the war against the Reapers, the Master Chief, Cortana, Teana, and Commander Shepard investigate rumors of activity from the Covenant terrorist faction led by the anti-human Sangheili kaidon Jul Mdama. Following the intel, the quartet stumbles upon a Forerunner artificial world with an ancient secret buried within. But some secrets are better left buried...