As was witnessed during the events of Halo: Combat Evolved and depicted in the Halo Graphic Novel, the Last Voyage of the Infinite Succor, at some point during the Feral Stage, the Flood begin to collectively shift their objective. When this happens, Combat Forms will work together to accumulate the biomass of both infected victims and uninfected sentient beings, allowing a series of widespread chemical reactions to occur across the reserves of calcium and flesh they have collected, eventually creating what is known as a Proto-Gravemind. Once a Proto-Gravemind absorbs enough biomass and becomes a fully grown Gravemind, the infection can then proceed into the Coordinated Stage.