Early in the Human-Covenant War, Spartan-II Blue Team is deployed in secret to the surface of Alpha Corvi II, which is under siege by the Covenant. Their mission is to fight off the Covenant forces and determine what they are searching for on the planet. During the mission, Blue Team allies with insurrectionist forces against the Covenant, who fight valiantly, but are ultimately killed in the battle. Blue Team escapes, but never finds what the Covenant was searching for.
Collateral Damage focuses on Blue Team and the early days of the Human-Covenant War.