Over a short amount of time, several unmanned human freighters in the Epsilon Indi system had been boarded and ransacked by what was believed to be Insurrectionist pirates. At the same time, Insurrectionist forces bombed the National Holiday over Reach, resulting in over a thousand fatalities. The UNSC decided they would not allow the Insurrectionists to conduct any further violence. After the disappearance of the manned freighter This End Up, the Office of Naval Intelligence authorized an investigation into the matter, expecting that insurrectionists were the boarders.
Jilan al-Cygni, an ONI agent, set up a trap for the boarders: lure them to an unmanned freighter over Harvest, and ambush them. The UNSC ambushers would be Staff Sergeants Avery Johnson and Nolan Byrne. Al-Cygni had an arsenal of weapons onboard her ship, the UNSC Walk of Shame, including some that had not been used in combat before, and the Walk of Shame itself was armed with one Archer Missile.
Johnson and Byrne, armed with Prototype BR55s and outfitted with Vacuum suits, moved into position but quickly saw that the boarders were not Insurrectionists: they were four Kig-Yar. Johnson asked for further orders, and Al-Cygni ordered that they continue to engage them, but they should try to capture one, and under no circumstances should any be allowed to escape. The two Marines engaged the Aliens: Byrne wounded one, but was wounded by another Kig-yar armed with an Energy cutlass. Johnson shot another and killed it with its own blade (which detonated). Johnson tended to Byrne's wounds and finished off the wounded Kig-yar. The last remaining Kig-yar (Chur'R-Yar, the captain of the Minor Transgression) retreated onto the Minor Transgression, and Johnson followed her and then killed her. He then left the Minor Transgression, which was destroyed by Chur'R in an attempt to cause to ship to self-destruct. Only two crew members survived the blast: the Deacon Dadab, and the Huragok Lighter Than Some, who fled the ship in an escape pod.
After the battle, the UNSC tried to make peace with the Covenant through pictograms. However, this failed when the Covenant leadership learned that Humanity were descendants of the Forerunners, and decided that they must be exterminated in order to preserve the foundation of the Covenant.