Tess was caught selling the Gjallerhorn on the black market to the hive on the moon. Oryx would not allow them to join his fireteam without it and Tess could not resist the temptation to supplement her income due to the poor pay in the tower. She had access to this firepower because she has been having an affair with Xur who has a surplus because he is no longer allowed to sell un-nerfed op weapons. She has been collected by Bungie for reconditioning and will return when her programming is complete.