In Halo Season 2 finale, Spartan-IIIs battle the Flood infection, leading to several Spartan-III deaths and setting up the third season.

In the Halo Season 2 finale, the Spartan-IIIs face off against Admiral Parangosky's mission against the Flood infection, resulting in several Spartan-III deaths. The Flood infection spreads rapidly, causing a terrifying hive mind, and characters Laera and Kai make self-sacrificing choices to save their comrades. The finale sets the stage for the third season, with the Flood serving as the key antagonist.