Warning: The following contains SPOILERS for Titans, season 2, episode 11, "E.L._.O."
The latest episode of Titans ended with two revelations about Rose Wilson, including that she's working for Deathstroke - except he has been possessed by Jericho. The whereabouts of Jason Todd and Rose Wilson (who had been absent from the show for the better part of two episodes) were revealed in Titans, season 2, episode 11, "E.L._.O."
Jason and Rose were hiding out in a house just outside of Gotham City, where they had been staying up all night fighting drug dealers and spending all day sleeping in and getting to know one another better. While Rose was receptive to the amorous young Robin's physical advances, she resisted his attempts at true intimacy and talking to her about her past.
Rose's attitude changed after Jason showed her the place he lived before he was adopted by Bruce Wayne; a space he built for himself in the fly space of a Gotham City high school's theater. Rose was something of a theater geek as well and shared Jason's love of West Side Story. This seemingly inspired her, near the end of the episode, to call Deathstroke/Jericho and tell him that she wanted out of "this little game you're playing with the Titans."
Rose being a traitor isn't too much of a revelation itself, as it beggared belief that she would just happen to show up where and when she did in the first place if it weren't part of a set-up, and there was no clear reason for Deathstroke to be trying to kill his daughter. However, the confirmation that Rose was a spy does explain many of Rose's actions, which only seemed to sow division among the Titans' ranks, such as her encouraging Beast Boy and Raven to spy on their elders to learn about the team's earlier encounters with Deathstroke. It also explained an apparent plot-hole from earlier in the season, where Rose showed no reaction to Hank Hall's discussing how the Titans were responsible for Jericho dying in episode 5, "Deathstroke," yet she threw a fit in episode 7, "Bruce Wayne" when she found her brother's records in Jason's collection and "suddenly realized" the Titans were the bad crowd who had gotten her brother killed.
It is worth mentioning that both these plot lines are taken directly from the Teen Titans comics of the early 21st century. Perhaps not coincidentally, these stories were written by Geoff Johns, who is now an executive producer on Titans. Regardless, it will be interesting to see how the heroes respond to both revelations and if the real Slade Wilson will take control again.