Warning: spoilers ahead for Episode 15 of Arrow Season 6, called "Doppelganger."
Arrow finally brought the long-lost Roy back into the mix in "Doppelganger," but the poor guy had a rough ride before he got to reunite with his friends on Team Arrow. The corrupt cops of the Star City Police Department tracked Roy down and abducted him to try and torture him into testifying that Oliver is the Green Arrow. Roy is obviously too loyal to turn on his former mentor (and the brother of the love of his life), so he had to endure torture via blunt object and phone book for far too long. The good news is that Thea ultimately managed to rescue from from Ricardo Diaz. The sad news is that Roy's arrival may mean the beginning of the end for another character: Thea herself.
At least this time around, the potential loss of Thea isn't due to being skewered by a giant sword or blown up by a psychopath on an island. No, Thea may soon be gone from Arrow because she leaves of her own free will, hopefully alive and healthy. She was frantic and determined for the majority of "Doppelganger" once Team Arrow discovered that Roy had been captured, and Roy almost certainly would not have been rescued if not for Thea leading the charge. Even when Oliver and Diggle seemed more concerned with nabbing Diaz and Anatoly than saving Roy, good old Thea kept her eye on the prize, and Roy was back safe and sound in the Arrow bunker after the raid on Diaz' base was completed.
The two ended up in bed together in the final moments of the episode in a shockingly happy ending for this show. Unfortunately, the camera panned away to a woman in League of Assassins garb spying on them from outside, and the preview for the next episode indicates that Thea will be targeted yet again due to her status as the daughter of Malcolm Merlyn, but a quiet scene between Oliver and Thea set the stage for Thea to depart following the conclusion of this arc. When Team Arrow hit a dead end on finding Roy and they could only wait for results, Oliver had a heart-to-heart with his little sister that actually showed a lot of growth on his part. After Thea confessed that she hasn't felt complete since Roy left, Oliver suggested that when Roy has to go on the run again, she goes with him.
Thea was taken aback that her protective big brother was giving her the green light (not that she needed it) to join Roy in the fugitive life, but the stability of his personal life after finally marrying Felicity seems to have given Oliver some perspective, and he acknowledged that Thea might need more from her life than what she could get in Star City. Roy is the one that got away for her and he clearly reciprocates her feelings. If Thea leaves Star City, it will obviously be sad for Team Arrow as well as for fans who have gotten used to having Willa Holland as a regular for the past six seasons of the show, but running away with Roy is possibly the closest she could possibly get to a happily-ever-after, and they both certainly deserve a happy ending. A big goodbye could be on the way, and we may want to prepare ourselves.
She hasn't left yet, however, and the next episode should give her a lot to do with the League of Assassins back in the mix. Nyssa will be back as well, which probably means we're in for some epic action sequences. Tune in to The CW on Thursdays at 9 p.m. ET for new episodes of Arrow. If you're still in the market for other shows, take a look at our midseason TV premiere guide. If streaming is more your style, our handy Netflix premiere schedule and 2018 Amazon Prime schedule can help you out.