Xur wanted to be part of the destabilization of Idenolid, so he got himself assigned to a division of the Armada devoted to those kinds of missions. Zane was friends with him, so he followed. The Rockmind task force wasn't their only covert mission. Another was the Lightsnare task force, where their team was sent to the pre-contact, low-tech planet Urigol with orders to acquire their radgun technology. It was a dangerous planet and a dangerous mission, and most of Lightsnare didn't come back. Engineer Elwan, their civilian consultant, was killed. Aspirant Galar was driven violently insane by the poisons in the water. Lieutenant Morag, the leader of the task force, disappeared one night and couldn't be found. Only Sub-Lieutenant Zane and Midshipman Xur returned. Unknown to them, Morag disappeared because she'd been given a secret mission. That mission completed, she's looking for a way home. Edit: Changed the lieutenant's name to Morag.