Halo Nation

Hydra (code)

10,043pages on
this wiki
Add New Page
Talk0 Share

Hydra was a UNSC general Emergency code. It was almost never used due to its content. The Hydra code word signifies imminent threat from biological weapons of mass destruction.[1]

Cortana used Slipspace to declare code Hydra after the discovery of Installation 05 and its escaped Flood. The threat came from both the potential for the Halo's activation and the loose Flood that posed a significant threat to all life.[1]


  1. 1.0 1.1 Halo: Ghosts of Onyx, page 183: "Hydra," however, she had never heard used before. It was reserved for imminent threat from biological weapons of mass destruction.

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.