Omega three

Code Omega Three was a UNSC emergency code. This code, to be used during combat operations, chilled any soldier to the core.

Omega Three was the final panic code, an order to break and run no matter what the cost. This code was used only in extreme situations, when a combat situation suddenly turned extremely grim for the UNSC forces and they would be massacred if they did not immediately retreat.

It was used in Operation TORPEDO in 2545 when seven Covenant cruisers arrived on Pegasi Delta to halt the Spartan-III's attack. Except Tom and Lucy, who managed to jump into the water before they were hit, all of the Spartan-III's were killed by the Cleansing Beam of the Cruisers.