— Dersau to Baird when he stood between Polyps and her flamethrower
Fifteen years after Emergence Day, Dersau worked aboard the Emerald Spar Imulsion Platform. When they were warned they were about to come under attack by LambentStalks, she began helping other crew members load weapons with ammo. After Stefan Gradin briefed them, Dersau began asking Cpl. Damon Baird questions about the Lambent Polyps, learning how they were quick but couldn't swim, but didn't drown quickly. She decided to treat them like cockroaches, and use a flamethrower to deal with them. As they waited for the Stalk to arrive at the platform, Dersau talked with Cpl. Dominic Santiago, but she also had a large space to herself, with no one wanting to get accidently burned by her flamethrower. Once the battle kicked off, Dersau headed into the corridors of the platform to clear out the Polyps. She clung to a ladder in order to pour fire down onto a group of Polyps, nearly burning Baird and Pvt. Augustus Cole in the process. When the Polyps exploded, they took a section of the bulkhead and ladder with them. She was left hanging over an abyss while Baird, Cole, and Pvt. Samantha Byrne covered her from above. Once all the Polyps were taken care of, Baird and Cole lifted her up off of the ladder. She then requested cover while she went onto a bridge to burn the Polyps on the lower decks. After the Emerald Spar was overrun and evacuated, Dersau was among several people pulled out of the water by the evacuation boat. She had lost her flamethrower, and allowed Cole to wrap her in a blanket.