The second episode of Halo throws us back to the earlier days of Master Chief's life—I mean, not so far back as to give us a visual of an armored-up Baby Chief, but far enough to give us a better sense of Chief's changed psyche.
Getting ready for bed as a young man in the UNSC, Chief notices that the bed labeled "066" is missing its occupant, Soren (Bokeem Woodbine), who's Chief's best friend. He leaves to find Soren on the brink of leaving the UNSC base for good, as they had apparently agreed to leave together. As Chief hasn't brought his armor or ditch bag, it's clear to Soren that his friend won't be joining him. Soren tries to convince him to leave while Chief pleads with him to stay, though Soren is set in his ways—and so is Chief. Finally, Chief pulls a gun out on him, though he has a slight change of heart and decides to not to kill Soren, telling him instead that he has five minutes to leave before he alerts the authorities.
Back in the present day, Chief and Kwan are out on the loose as they were narrowly able to escape the UNSC headquarters just before. Though it's at first unclear where exactly they're headed in their ship, Chief has a whole plan figured out in his head.
There's an almost extreme quietness as they head through the asteroids in space, but Chief finally settles on a specific one to hone his sights on. Landing on the Rubble, a city on an asteroid, Chief meets up with none other than Soren, who seems to be living a particularly happy life after having left the UNSC.
We switch our gears to High Charity (a planet that houses the Covenant), where plans are being put in motion to steal back the artifact that Chief took from Madrigal. The Covenant clearly understands the full capabilities of the artifact's powers and are desperate to get it back. Also, apparently what I've been referring to as the "artifact" is actually considered the "relic," so from here on out, we're going with "relic." The relic is part of one of the main keystones, which is why it's so valuable to the Covenant. And at the Rubble, one of Chief's main goals is to figure out just what that relic is capable of.