Anarosa

Anarosa is one of several short stories in Halo: Fractures - Extraordinary Tales from the Halo Canon.

Official summary
"This story takes place in March 2556, three years after the end of the Covenant War (Halo 3 era) and one year after FAR STORM, a joint military operation between humans and their former Sangheili enemies in order to secure the remote and mysterious Forerunner installation known as the Ark (Halo: Hunters in the Dark)."