Sigma-4 was a Gear squad that accompanied Delta-One on a mission outside of Port Farrall to find and kill a wounded Locust Drone. Several members of the squad were killed or wounded, among them Collin, during an ambush by the Locust.
After the Sinking of Jacinto, the COG relocated to Port Farrall. Six and a half weeks later, Sigma-4 and Delta-One were tasked with finding and killing a Drone wounded by Sgt. Rory Andresen. One of the Gears in the squad, Collin, found a blood trail from the Drone. However, several other blood trails were found, and when Cpl. Baird heard a Kantus, the two squads suddenly found themselves under attack. The Locust herded them into groups of mines, killing several of the squad. Collin was wounded, and watched over by another squad member. Bravo-Three came to their rescue, but a second group of Locust arrived in the form of a large number of Boomers. The Gears managed to defeat them when the Kantus were killed, but most of Sigma-4 had been killed in the ambush.
- Collin - WIA