Battle of the Maginot Sphere

"Mendicant has burrowed through the sphere exactly where I expected - a direct path from initial rampancy to final retribution. Rage has made it predictable."

- Didact

The Battle of Maginot Sphere was a naval battle in the Forerunner-Flood War. It marked a turning point in the war — the Flood had stopped feeding and expanding, and instead, were devoting their efforts to penetrating the last Forerunner line of defense, the Maginot Sphere, to complete the destruction of the Forerunners.

Prelude
The battle was preceded by the rampancy of the Forerunner artificial intelligence Mendicant Bias, who after a protracted intelligent conversation with the Flood, had decided that the Flood were the next step of evolution for galactic life, and that the Forerunners were corrupt for resisting this inevitable evolution and for refusing to be supplanted by their biologically superior adversary. Mendicant declared his allegiance with the Flood and defamed the Forerunners, and not only lended his tactical intelligence to the Flood, directing their fleets, but also gave the thousand Forerunner-crewed vessels under his command to the Flood.